diff --git a/README.md b/README.md
index 99d2139..57a081b 100644
--- a/README.md
+++ b/README.md
@@ -5,13 +5,11 @@ Easy autofixable import sorting.
 - ✔️ Runs via `eslint --fix` – no new tooling
 - ✔️ Handles comments
 - ✔️ Handles [Flow type imports] \(via [babel-eslint])
-- ✔️ Handles [webpack loader syntax]
 - ✔️ [TypeScript] friendly \(via [@typescript-eslint/parser])
 - ✔️ [Prettier] friendly
 - ✔️ [eslint-plugin-import] friendly
 - ✔️ `git diff` friendly
 - ✔️ 100% code coverage
-- ☯️ No configuration
 - ❌ [Does not support `require`][no-require]
 
 This is for those who use `eslint --fix` (autofix) a lot and want to completely
@@ -29,6 +27,7 @@ forget about sorting imports!
 - [Usage](#usage)
 - [Example configuration](#example-configuration)
 - [Sort order](#sort-order)
+- [Custom grouping](#custom-grouping)
 - [Comment and whitespace handling](#comment-and-whitespace-handling)
 - [FAQ](#faq)
   - [Does it support `require`?](#does-it-support-require)
@@ -213,10 +212,13 @@ Then, each chunk is _grouped_ into sections with a blank line between each.
 
 1. `import "./setup"`: Side effect imports. (These are not sorted internally.)
 2. `import react from "react"`: Packages (npm packages and Node.js builtins).
-3. `import a from "/a"`: Absolute imports, full URLs and other imports (such as
-   Vue-style `@/foo` ones).
+3. `import a from "/a"`: Absolute imports and other imports such as Vue-style
+   `@/foo`.
 4. `import a from "./a"`: Relative imports.
 
+Note: The above groups are very loosely defined. See [Custom grouping] for more
+information.
+
 Within each section, the imports are sorted alphabetically on the `from` string
 (see also [“Why sort on `from`?”][sort-from]). Keep it simple! It helps looking
 at the code here:
@@ -242,13 +244,10 @@ structure come before closer ones – `"../../utils"` comes before `"../utils"`.
 Perhaps surprisingly though, `".."` would come before `"../../utils"` (since
 shorter substrings sort before longer strings). For that reason there’s one
 addition to the alphabetical rule: `"."` and `".."` are treated as `"./"` and
-`"../"`. Also, within the absolute imports group, imports starting with an ASCII
-letter or digit come first, separating them from those starting with symbols.
+`"../"`.
 
-[webpack loader syntax] is stripped before sorting, so `"loader!a"` sorts before
-`"b"`. If two sources are equal after stripping the loader syntax, the one with
-loader syntax comes last. Similarly, if both `import type` _and_ regular imports
-are used for the same source, the [Flow type imports] come first.
+If both `import type` _and_ regular imports are used for the same source, the
+[Flow type imports] come first.
 
 Example:
 
@@ -263,9 +262,9 @@ import "./global.css";
 import type A from "an-npm-package";
 import a from "an-npm-package";
 import fs from "fs";
-
-// Absolute imports, full URLs and other imports.
 import b from "https://example.com/script.js";
+
+// Absolute imports and other imports.
 import Error from "@/components/error.vue";
 import c from "/";
 import d from "/home/user/foo";
@@ -278,7 +277,6 @@ import typeof C from "../types";
 import g from ".";
 import h from "./constants";
 import i from "./styles";
-import j from "html-loader!./text.html";
 
 // Regardless of group, imported items are sorted like this:
 import {
@@ -304,6 +302,97 @@ Workaround to make the next section to appear in the table of contents.
 ```
 -->
 
+## Custom grouping
+
+For a long time, this plugin used to have no options, which helped keeping it
+simple.
+
+While the human alphabetical sorting and comment handling seems to work for a
+lot of people, grouping of imports is more difficult. Projects differ too much
+to have a one-size-fits-all grouping.
+
+However, the default grouping is fine for many use cases! Don’t bother learning
+how custom grouping works unless you _really_ need it.
+
+> If you’re looking at custom grouping because you want to move `src/Button`,
+> `@company/Button` and similar – also consider using names that do not look
+> like npm packages, such as `@/Button` and `~company/Button`. Then you won’t
+> need to customize the grouping at all, and as a bonus things might be less
+> confusing for other people working on the code base.
+>
+> In the future, it would be cool if the plugin could automatically detect your
+> “first party”/“absolute” imports for TypeScript projects by reading your
+> tsconfig.json – see [issue #31].
+
+There is **one** option (and I would really like it to stay that way!) called
+`groups` that allows you to:
+
+- Move `src/Button`, `@company/Button` and similar out of the (third party)
+  “packages” group, into their own group.
+- Move `react` first.
+- Remove blank lines between groups.
+- Make a separate group for Node.js builtins.
+- Make a separate group for style imports.
+- Separate `./` and `../` imports.
+- Not use groups at all and only sort alphabetically.
+
+`groups` is an array of arrays of strings:
+
+```ts
+type Options = {
+  groups: Array<Array<string>>;
+};
+```
+
+Each string is a regex (with the `u` flag) and defines a group. (Remember to
+escape backslashes – it’s `"\\w"`, not `"\w"`, for example.)
+
+Each `import` is matched against _all_ regexes on the `from` string. The import
+ends up in the group with **the longest match.** In case of a tie, the first
+matching group wins.
+
+> If an import ends up in the wrong group – try making the desired group regex
+> match more of the `from` string, or use negative lookahead (`(?!x)`) to
+> exclude things from other groups.
+
+Imports that don’t match any regex are grouped together last.
+
+Side effect imports have `\u0000` prepended to their `from` string. You can
+match them with `"^\\u0000"`.
+
+The inner arrays are joined with one newline; the outer arrays are joined with
+two (creating a blank line).
+
+Every group is sorted internally as mentioned in [Sort order]. Side effect
+imports are sorted too – but will keep their internal order. It’s recommended to
+keep side effect imports in their own group.
+
+These are the default groups:
+
+```js
+[
+  // Side effect imports.
+  ["^\\u0000"],
+  // Packages.
+  // Things that start with a letter (or digit or underscore), or `@` followed by a letter.
+  ["^@?\\w"],
+  // Absolute imports and other imports such as Vue-style `@/foo`.
+  // Anything that does not start with a dot.
+  ["^[^.]"],
+  // Relative imports.
+  // Anything that starts with a dot.
+  ["^\\."],
+];
+```
+
+The astute reader might notice that the above regexes match more than their
+comments say. For example, `"@config"` and `"_internal"` are matched as
+packages, but none of them are valid npm package names. `".foo"` is matched as a
+relative import, but what does `".foo"` even mean? There’s little gain in having
+more specific rules, though. So keep it simple!
+
+See the [examples] for inspiration.
+
 ## Comment and whitespace handling
 
 When an import is moved through sorting, it’s comments are moved with it.
@@ -332,11 +421,11 @@ import b from "b"; // b2
 // comment before import chunk
 // a1
 /* a2
- */ import a /* a3 */ from "a"; /* a4 */
+ */ import a /* a3 */ from "a"; /* a4 */ 
 // b1
 import b from "b"; // b2
 /* c1 */ import c from "c"; // c2
- /* not-a
+/* not-a
 */ // comment after import chunk
 ```
 
@@ -574,6 +663,7 @@ You can need [Node.js] 10 and npm 6.
 [@typescript-eslint/parser]: https://github.com/typescript-eslint/typescript-eslint/tree/master/packages/parser
 [babel-eslint]: https://github.com/babel/babel-eslint
 [comment-handling]: #comment-and-whitespace-handling
+[custom grouping]: #custom-grouping
 [doctoc]: https://github.com/thlorenz/doctoc/
 [eslint-fix]: https://eslint.org/docs/user-guide/command-line-interface#--fix
 [eslint-plugin-import]: https://github.com/benmosher/eslint-plugin-import/
@@ -589,6 +679,7 @@ You can need [Node.js] 10 and npm 6.
 [import/no-duplicates]: https://github.com/benmosher/eslint-plugin-import/blob/master/docs/rules/no-duplicates.md
 [import/order]: https://github.com/benmosher/eslint-plugin-import/blob/master/docs/rules/order.md
 [intl.collator]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Collator
+[issue #31]: https://github.com/lydell/eslint-plugin-simple-import-sort/issues/31
 [jest]: https://jestjs.io/
 [lines-around-comment]: https://eslint.org/docs/rules/lines-around-comment
 [no-require]: #does-it-support-require
@@ -604,5 +695,4 @@ You can need [Node.js] 10 and npm 6.
 [travis-badge]: https://travis-ci.com/lydell/eslint-plugin-simple-import-sort.svg?branch=master
 [travis-link]: https://travis-ci.com/lydell/eslint-plugin-simple-import-sort
 [typescript]: https://www.typescriptlang.org/
-[webpack loader syntax]: https://webpack.js.org/concepts/loaders/#inline
 <!-- prettier-ignore-end -->
diff --git a/examples/.eslintrc.js b/examples/.eslintrc.js
index 3608073..3a118b9 100644
--- a/examples/.eslintrc.js
+++ b/examples/.eslintrc.js
@@ -53,7 +53,7 @@ module.exports = {
       rules: {
         "import/first": "error",
         "import/newline-after-import": "error",
-        "import/no-duplicates": "error"
+        "import/no-duplicates": "error",
       },
     },
     {
@@ -65,6 +65,59 @@ module.exports = {
         "import/no-duplicates": "error",
       },
     },
+    {
+      files: ["groups.custom.js"],
+      rules: {
+        sort: [
+          "error",
+          {
+            groups: [
+              // Node.js builtins. You could also generate this regex if you use a `.js` config.
+              // For example: `^(${require("module").builtinModules.join("|")})(/|$)`
+              [
+                "^(assert|buffer|child_process|cluster|console|constants|crypto|dgram|dns|domain|events|fs|http|https|module|net|os|path|punycode|querystring|readline|repl|stream|string_decoder|sys|timers|tls|tty|url|util|vm|zlib|freelist|v8|process|async_hooks|http2|perf_hooks)(/.*|$)",
+              ],
+              // Packages. `react` related packages come first.
+              ["^react", "^@?\\w"],
+              // Internal packages.
+              ["^(@|@company|@ui|components|utils|config|vendored-lib)(/.*|$)"],
+              // Side effect imports.
+              ["^\\u0000"],
+              // Parent imports. Put `..` last.
+              ["^\\.\\.(?!/?$)", "^\\.\\./?$"],
+              // Other relative imports. Put same-folder imports and `.` last.
+              ["^\\./(?=.*/)(?!/?$)", "^\\.(?!/?$)", "^\\./?$"],
+              // Style imports.
+              ["^.+\\.s?css$"],
+            ],
+          },
+        ],
+      },
+    },
+    {
+      files: ["groups.no-blank-lines.js"],
+      rules: {
+        sort: [
+          "error",
+          {
+            // The default grouping, but with no blank lines.
+            groups: [["^\\u0000", "^@?\\w", "^[^.]", "^\\."]],
+          },
+        ],
+      },
+    },
+    {
+      files: ["groups.none.js"],
+      rules: {
+        sort: [
+          "error",
+          {
+            // No grouping, only alphabetical sorting.
+            groups: [],
+          },
+        ],
+      },
+    },
     {
       // These files are used in README.md.
       files: ["readme-*.js"],
diff --git a/examples/groups.custom.js b/examples/groups.custom.js
new file mode 100644
index 0000000..d6370ac
--- /dev/null
+++ b/examples/groups.custom.js
@@ -0,0 +1,26 @@
+import fs from "fs";
+import assert from "assert";
+import react from "react";
+import Select from "react-select"
+import _ from "lodash"
+import {providers} from "./providers"
+import tomorrow from "./time/tomorrow"
+import now from "./time/now"
+import {PRODUCT_NAMES} from "."
+import {CATEGORIES} from "../"
+import {truncate, removeWhitespace} from "../../utils";
+import cssGlobals from "../../css/globals"
+import styles from "./styles.scss";
+import circleSyles from "./circle.scss";
+import "./global.scss"
+import {name} from "@company/config"
+import Button from "@ui/Button";
+import Label from "components/Label"
+import {pluralize} from "utils/string"
+import {API_URL} from "config";
+import VendoredLib from "vendored-lib"
+import createWrapper from "vendored-lib/lib/create-wrapper"
+import Textarea from "@/ui/Textarea"
+import "./local-polyfill"
+import "polyfill-package"
+import "../../alert.css"
diff --git a/examples/groups.no-blank-lines.js b/examples/groups.no-blank-lines.js
new file mode 100644
index 0000000..c29336c
--- /dev/null
+++ b/examples/groups.no-blank-lines.js
@@ -0,0 +1,10 @@
+import React from "react";
+import Button from "../Button";
+
+import styles from "./styles.css";
+import { User } from "../../types";
+import { getUser } from "../../api";
+
+import PropTypes from "prop-types";
+import classnames from "classnames";
+import { truncate, formatNumber } from "../../utils";
diff --git a/examples/groups.none.js b/examples/groups.none.js
new file mode 100644
index 0000000..15ab067
--- /dev/null
+++ b/examples/groups.none.js
@@ -0,0 +1,5 @@
+import react from "react";
+import { storiesOf } from "@storybook/react";
+import App from "@/App";
+import styles from "./styles";
+import config from "/config";
diff --git a/examples/readme-order.js b/examples/readme-order.js
index 34a2d73..8b62b54 100644
--- a/examples/readme-order.js
+++ b/examples/readme-order.js
@@ -7,9 +7,9 @@ import "./global.css";
 import type A from "an-npm-package";
 import a from "an-npm-package";
 import fs from "fs";
-
-// Absolute imports, full URLs and other imports.
 import b from "https://example.com/script.js";
+
+// Absolute imports and other imports.
 import Error from "@/components/error.vue"
 import c from "/";
 import d from "/home/user/foo";
@@ -22,7 +22,6 @@ import typeof C from "../types";
 import g from ".";
 import h from "./constants";
 import i from "./styles";
-import j from "html-loader!./text.html";
 
 // Regardless of group, imported items are sorted like this:
 import {
diff --git a/package-lock.json b/package-lock.json
index 6c10603..40f0de7 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -529,51 +529,57 @@
       "dev": true
     },
     "@typescript-eslint/experimental-utils": {
-      "version": "2.6.0",
-      "resolved": "https://registry.npmjs.org/@typescript-eslint/experimental-utils/-/experimental-utils-2.6.0.tgz",
-      "integrity": "sha512-34BAFpNOwHXeqT+AvdalLxOvcPYnCxA5JGmBAFL64RGMdP0u65rXjii7l/nwpgk5aLEE1LaqF+SsCU0/Cb64xA==",
+      "version": "2.8.0",
+      "resolved": "https://registry.npmjs.org/@typescript-eslint/experimental-utils/-/experimental-utils-2.8.0.tgz",
+      "integrity": "sha512-jZ05E4SxCbbXseQGXOKf3ESKcsGxT8Ucpkp1jiVp55MGhOvZB2twmWKf894PAuVQTCgbPbJz9ZbRDqtUWzP8xA==",
       "dev": true,
       "requires": {
         "@types/json-schema": "^7.0.3",
-        "@typescript-eslint/typescript-estree": "2.6.0",
+        "@typescript-eslint/typescript-estree": "2.8.0",
         "eslint-scope": "^5.0.0"
-      },
-      "dependencies": {
-        "eslint-scope": {
-          "version": "5.0.0",
-          "resolved": "https://registry.npmjs.org/eslint-scope/-/eslint-scope-5.0.0.tgz",
-          "integrity": "sha512-oYrhJW7S0bxAFDvWqzvMPRm6pcgcnWc4QnofCAqRTRfQC0JcwenzGglTtsLyIuuWFfkqDG9vz67cnttSd53djw==",
-          "dev": true,
-          "requires": {
-            "esrecurse": "^4.1.0",
-            "estraverse": "^4.1.1"
-          }
-        }
       }
     },
     "@typescript-eslint/parser": {
-      "version": "2.6.0",
-      "resolved": "https://registry.npmjs.org/@typescript-eslint/parser/-/parser-2.6.0.tgz",
-      "integrity": "sha512-AvLejMmkcjRTJ2KD72v565W4slSrrzUIzkReu1JN34b8JnsEsxx7S9Xx/qXEuMQas0mkdUfETr0j3zOhq2DIqQ==",
+      "version": "2.8.0",
+      "resolved": "https://registry.npmjs.org/@typescript-eslint/parser/-/parser-2.8.0.tgz",
+      "integrity": "sha512-NseXWzhkucq+JM2HgqAAoKEzGQMb5LuTRjFPLQzGIdLthXMNUfuiskbl7QSykvWW6mvzCtYbw1fYWGa2EIaekw==",
       "dev": true,
       "requires": {
         "@types/eslint-visitor-keys": "^1.0.0",
-        "@typescript-eslint/experimental-utils": "2.6.0",
-        "@typescript-eslint/typescript-estree": "2.6.0",
+        "@typescript-eslint/experimental-utils": "2.8.0",
+        "@typescript-eslint/typescript-estree": "2.8.0",
         "eslint-visitor-keys": "^1.1.0"
       }
     },
     "@typescript-eslint/typescript-estree": {
-      "version": "2.6.0",
-      "resolved": "https://registry.npmjs.org/@typescript-eslint/typescript-estree/-/typescript-estree-2.6.0.tgz",
-      "integrity": "sha512-A3lSBVIdj2Gp0lFEL6in2eSPqJ33uAc3Ko+Y4brhjkxzjbzLnwBH22CwsW2sCo+iwogfIyvb56/AJri15H0u5Q==",
+      "version": "2.8.0",
+      "resolved": "https://registry.npmjs.org/@typescript-eslint/typescript-estree/-/typescript-estree-2.8.0.tgz",
+      "integrity": "sha512-ksvjBDTdbAQ04cR5JyFSDX113k66FxH1tAXmi+dj6hufsl/G0eMc/f1GgLjEVPkYClDbRKv+rnBFuE5EusomUw==",
       "dev": true,
       "requires": {
         "debug": "^4.1.1",
-        "glob": "^7.1.4",
+        "eslint-visitor-keys": "^1.1.0",
+        "glob": "^7.1.6",
         "is-glob": "^4.0.1",
         "lodash.unescape": "4.0.1",
-        "semver": "^6.3.0"
+        "semver": "^6.3.0",
+        "tsutils": "^3.17.1"
+      },
+      "dependencies": {
+        "glob": {
+          "version": "7.1.6",
+          "resolved": "https://registry.npmjs.org/glob/-/glob-7.1.6.tgz",
+          "integrity": "sha512-LwaxwyZ72Lk7vZINtNNrywX0ZuLyStrdDtabefZKAY5ZGJhVtgdznluResxNmPitE0SAO+O26sWTHeKSI2wMBA==",
+          "dev": true,
+          "requires": {
+            "fs.realpath": "^1.0.0",
+            "inflight": "^1.0.4",
+            "inherits": "2",
+            "minimatch": "^3.0.4",
+            "once": "^1.3.0",
+            "path-is-absolute": "^1.0.0"
+          }
+        }
       }
     },
     "abab": {
@@ -607,9 +613,9 @@
       }
     },
     "acorn-jsx": {
-      "version": "5.0.2",
-      "resolved": "https://registry.npmjs.org/acorn-jsx/-/acorn-jsx-5.0.2.tgz",
-      "integrity": "sha512-tiNTrP1MP0QrChmD2DdupCr6HWSFeKVw5d/dHTu4Y7rkAkRhU/Dt7dphAfIUyxtHpl/eBVip5uTNSpQJHylpAw==",
+      "version": "5.1.0",
+      "resolved": "https://registry.npmjs.org/acorn-jsx/-/acorn-jsx-5.1.0.tgz",
+      "integrity": "sha512-tMUqwBWfLFbJbizRmEcWSLw6HnFzfdJs2sOJEOwwtVPMoH/0Ay+E703oZz78VSXZiiDcZrQ5XKjPIUQixhmgVw==",
       "dev": true
     },
     "acorn-walk": {
@@ -1040,11 +1046,6 @@
       "integrity": "sha512-MQcXEUbCKtEo7bhqEs6560Hyd4XaovZlO/k9V3hjVUF/zwW7KBVdSK4gIt/bzwS9MbR5qob+F5jusZsb0YQK2A==",
       "dev": true
     },
-    "builtins": {
-      "version": "1.0.3",
-      "resolved": "https://registry.npmjs.org/builtins/-/builtins-1.0.3.tgz",
-      "integrity": "sha1-y5T662HIaWRR2zZTThQi+U8K7og="
-    },
     "cache-base": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/cache-base/-/cache-base-1.0.1.tgz",
@@ -1834,9 +1835,9 @@
       }
     },
     "eslint-plugin-jest": {
-      "version": "23.0.2",
-      "resolved": "https://registry.npmjs.org/eslint-plugin-jest/-/eslint-plugin-jest-23.0.2.tgz",
-      "integrity": "sha512-fkxcvOJm0hC/jbJqYJjtuC9mvpTJqXd0Nixx7joVQvJoBQuXk/ws3+MtRYzD/4TcKSgvr21uuSLdwSxKJKC2cg==",
+      "version": "23.0.4",
+      "resolved": "https://registry.npmjs.org/eslint-plugin-jest/-/eslint-plugin-jest-23.0.4.tgz",
+      "integrity": "sha512-OaP8hhT8chJNodUPvLJ6vl8gnalcsU/Ww1t9oR3HnGdEWjm/DdCCUXLOral+IPGAeWu/EwgVQCK/QtxALpH1Yw==",
       "dev": true,
       "requires": {
         "@typescript-eslint/experimental-utils": "^2.5.0"
@@ -1863,18 +1864,18 @@
       }
     },
     "eslint-plugin-vue": {
-      "version": "5.2.3",
-      "resolved": "https://registry.npmjs.org/eslint-plugin-vue/-/eslint-plugin-vue-5.2.3.tgz",
-      "integrity": "sha512-mGwMqbbJf0+VvpGR5Lllq0PMxvTdrZ/ZPjmhkacrCHbubJeJOt+T6E3HUzAifa2Mxi7RSdJfC9HFpOeSYVMMIw==",
+      "version": "6.0.1",
+      "resolved": "https://registry.npmjs.org/eslint-plugin-vue/-/eslint-plugin-vue-6.0.1.tgz",
+      "integrity": "sha512-5tgFPcxGDKjfVB/6Yi56bKiWxygUibfZmzSh26Np3kuwAk/lfaGbVld+Yt+MPgD84ppvcachtiL4/winsXLjXA==",
       "dev": true,
       "requires": {
-        "vue-eslint-parser": "^5.0.0"
+        "vue-eslint-parser": "^6.0.5"
       }
     },
     "eslint-scope": {
-      "version": "4.0.3",
-      "resolved": "https://registry.npmjs.org/eslint-scope/-/eslint-scope-4.0.3.tgz",
-      "integrity": "sha512-p7VutNr1O/QrxysMo3E45FjYDTeXBy0iTltPFNSqKAIfjDSXC+4dj+qfyuD8bfAXrW/y6lW3O76VaYNPKfpKrg==",
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/eslint-scope/-/eslint-scope-5.0.0.tgz",
+      "integrity": "sha512-oYrhJW7S0bxAFDvWqzvMPRm6pcgcnWc4QnofCAqRTRfQC0JcwenzGglTtsLyIuuWFfkqDG9vz67cnttSd53djw==",
       "dev": true,
       "requires": {
         "esrecurse": "^4.1.0",
@@ -2963,9 +2964,9 @@
       "dev": true
     },
     "handlebars": {
-      "version": "4.4.5",
-      "resolved": "https://registry.npmjs.org/handlebars/-/handlebars-4.4.5.tgz",
-      "integrity": "sha512-0Ce31oWVB7YidkaTq33ZxEbN+UDxMMgThvCe8ptgQViymL5DPis9uLdTA13MiRPhgvqyxIegugrP97iK3JeBHg==",
+      "version": "4.5.3",
+      "resolved": "https://registry.npmjs.org/handlebars/-/handlebars-4.5.3.tgz",
+      "integrity": "sha512-3yPecJoJHK/4c6aZhSvxOyG4vJKDshV36VHp0iVCDVh7o9w2vwi3NSnL2MMPj3YdduqaBcu7cGbggJQM0br9xA==",
       "dev": true,
       "requires": {
         "neo-async": "^2.6.0",
@@ -4842,9 +4843,9 @@
       "dev": true
     },
     "prettier": {
-      "version": "1.18.2",
-      "resolved": "https://registry.npmjs.org/prettier/-/prettier-1.18.2.tgz",
-      "integrity": "sha512-OeHeMc0JhFE9idD4ZdtNibzY0+TPHSpSSb9h8FqtP+YnoZZ1sl8Vc9b1sasjfymH3SonAF4QcA2+mzHPhMvIiw==",
+      "version": "1.19.1",
+      "resolved": "https://registry.npmjs.org/prettier/-/prettier-1.19.1.tgz",
+      "integrity": "sha512-s7PoyDv/II1ObgQunCbB9PdLmUcBZcnWOcxDh7O0N/UwDEsHyqkW+Qh28jW+mVuCdx7gLB0BotYI1Y6uI9iyew==",
       "dev": true
     },
     "prettier-linter-helpers": {
@@ -6028,6 +6029,15 @@
       "integrity": "sha512-qOebF53frne81cf0S9B41ByenJ3/IuH8yJKngAX35CmiZySA0khhkovshKK+jGCaMnVomla7gVlIcc3EvKPbTQ==",
       "dev": true
     },
+    "tsutils": {
+      "version": "3.17.1",
+      "resolved": "https://registry.npmjs.org/tsutils/-/tsutils-3.17.1.tgz",
+      "integrity": "sha512-kzeQ5B8H3w60nFY2g8cJIuH7JDpsALXySGtwGJ0p2LSjLgay3NdIpqq5SoOBe46bKDW2iq25irHCr8wjomUS2g==",
+      "dev": true,
+      "requires": {
+        "tslib": "^1.8.1"
+      }
+    },
     "tunnel-agent": {
       "version": "0.6.0",
       "resolved": "https://registry.npmjs.org/tunnel-agent/-/tunnel-agent-0.6.0.tgz",
@@ -6059,15 +6069,15 @@
       "dev": true
     },
     "typescript": {
-      "version": "3.6.4",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-3.6.4.tgz",
-      "integrity": "sha512-unoCll1+l+YK4i4F8f22TaNVPRHcD9PA3yCuZ8g5e0qGqlVlJ/8FSateOLLSagn+Yg5+ZwuPkL8LFUc0Jcvksg==",
+      "version": "3.7.2",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-3.7.2.tgz",
+      "integrity": "sha512-ml7V7JfiN2Xwvcer+XAf2csGO1bPBdRbFCkYBczNZggrBZ9c7G3riSUeJmqEU5uOtXNPMhE3n+R4FA/3YOAWOQ==",
       "dev": true
     },
     "uglify-js": {
-      "version": "3.6.4",
-      "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.6.4.tgz",
-      "integrity": "sha512-9Yc2i881pF4BPGhjteCXQNaXx1DCwm3dtOyBaG2hitHjLWOczw/ki8vD1bqyT3u6K0Ms/FpCShkmfg+FtlOfYA==",
+      "version": "3.6.9",
+      "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.6.9.tgz",
+      "integrity": "sha512-pcnnhaoG6RtrvHJ1dFncAe8Od6Nuy30oaJ82ts6//sGSXOP5UjBMEthiProjXmMNHOfd93sqlkztifFMcb+4yw==",
       "dev": true,
       "optional": true,
       "requires": {
@@ -6270,14 +6280,6 @@
         "spdx-expression-parse": "^3.0.0"
       }
     },
-    "validate-npm-package-name": {
-      "version": "3.0.0",
-      "resolved": "https://registry.npmjs.org/validate-npm-package-name/-/validate-npm-package-name-3.0.0.tgz",
-      "integrity": "sha1-X6kS2B630MdK/BQN5zF/DKffQ34=",
-      "requires": {
-        "builtins": "^1.0.3"
-      }
-    },
     "verror": {
       "version": "1.10.0",
       "resolved": "https://registry.npmjs.org/verror/-/verror-1.10.0.tgz",
@@ -6317,15 +6319,15 @@
       }
     },
     "vue-eslint-parser": {
-      "version": "5.0.0",
-      "resolved": "https://registry.npmjs.org/vue-eslint-parser/-/vue-eslint-parser-5.0.0.tgz",
-      "integrity": "sha512-JlHVZwBBTNVvzmifwjpZYn0oPWH2SgWv5dojlZBsrhablDu95VFD+hriB1rQGwbD+bms6g+rAFhQHk6+NyiS6g==",
+      "version": "6.0.5",
+      "resolved": "https://registry.npmjs.org/vue-eslint-parser/-/vue-eslint-parser-6.0.5.tgz",
+      "integrity": "sha512-Bvjlx7rH1Ulvus56KHeLXOjEi3JMOYTa1GAqZr9lBQhd8weK8mV7U7V2l85yokBZEWHJQjLn6X3nosY8TzkOKg==",
       "dev": true,
       "requires": {
-        "debug": "^4.1.0",
+        "debug": "^4.1.1",
         "eslint-scope": "^4.0.0",
         "eslint-visitor-keys": "^1.0.0",
-        "espree": "^4.1.0",
+        "espree": "^5.0.0",
         "esquery": "^1.0.1",
         "lodash": "^4.17.11"
       },
@@ -6336,13 +6338,23 @@
           "integrity": "sha512-/czfa8BwS88b9gWQVhc8eknunSA2DoJpJyTQkhheIf5E48u1N0R4q/YxxsAeqRrmK9TQ/uYfgLDfZo91UlANIA==",
           "dev": true
         },
+        "eslint-scope": {
+          "version": "4.0.3",
+          "resolved": "https://registry.npmjs.org/eslint-scope/-/eslint-scope-4.0.3.tgz",
+          "integrity": "sha512-p7VutNr1O/QrxysMo3E45FjYDTeXBy0iTltPFNSqKAIfjDSXC+4dj+qfyuD8bfAXrW/y6lW3O76VaYNPKfpKrg==",
+          "dev": true,
+          "requires": {
+            "esrecurse": "^4.1.0",
+            "estraverse": "^4.1.1"
+          }
+        },
         "espree": {
-          "version": "4.1.0",
-          "resolved": "https://registry.npmjs.org/espree/-/espree-4.1.0.tgz",
-          "integrity": "sha512-I5BycZW6FCVIub93TeVY1s7vjhP9CY6cXCznIRfiig7nRviKZYdRnj/sHEWC6A7WE9RDWOFq9+7OsWSYz8qv2w==",
+          "version": "5.0.1",
+          "resolved": "https://registry.npmjs.org/espree/-/espree-5.0.1.tgz",
+          "integrity": "sha512-qWAZcWh4XE/RwzLJejfcofscgMc9CamR6Tn1+XRXNzrvUSSbiAjGOI/fggztjIi7y9VLPqnICMIPiGyr8JaZ0A==",
           "dev": true,
           "requires": {
-            "acorn": "^6.0.2",
+            "acorn": "^6.0.7",
             "acorn-jsx": "^5.0.0",
             "eslint-visitor-keys": "^1.0.0"
           }
diff --git a/package.json b/package.json
index c02877b..abffc33 100644
--- a/package.json
+++ b/package.json
@@ -31,24 +31,21 @@
     "test": "npm run eslint && npm run coverage",
     "prepublishOnly": "npm test"
   },
-  "dependencies": {
-    "validate-npm-package-name": "^3.0.0"
-  },
   "devDependencies": {
-    "@typescript-eslint/parser": "2.6.0",
+    "@typescript-eslint/parser": "2.8.0",
     "babel-eslint": "10.0.3",
     "cross-spawn": "7.0.1",
     "doctoc": "1.4.0",
     "eslint": "6.6.0",
     "eslint-config-lydell": "14.0.0",
     "eslint-plugin-import": "2.18.2",
-    "eslint-plugin-jest": "23.0.2",
+    "eslint-plugin-jest": "23.0.4",
     "eslint-plugin-markdown": "1.0.1",
     "eslint-plugin-prettier": "3.1.1",
-    "eslint-plugin-vue": "5.2.3",
+    "eslint-plugin-vue": "6.0.1",
     "jest": "24.9.0",
-    "prettier": "1.18.2",
-    "typescript": "3.6.4"
+    "prettier": "1.19.1",
+    "typescript": "3.7.2"
   },
   "peerDependencies": {
     "eslint": ">=5.0.0"
diff --git a/src/sort.js b/src/sort.js
index 6a592db..d4a56c8 100644
--- a/src/sort.js
+++ b/src/sort.js
@@ -1,12 +1,40 @@
 "use strict";
 
-const validateNpmPackageName = require("validate-npm-package-name");
+const defaultGroups = [
+  // Side effect imports.
+  ["^\\u0000"],
+  // Packages.
+  // Things that start with a letter (or digit or underscore), or `@` followed by a letter.
+  ["^@?\\w"],
+  // Absolute imports and other imports such as Vue-style `@/foo`.
+  // Anything that does not start with a dot.
+  ["^[^.]"],
+  // Relative imports.
+  // Anything that starts with a dot.
+  ["^\\."],
+];
 
 module.exports = {
   meta: {
     type: "layout",
     fixable: "code",
-    schema: [],
+    schema: [
+      {
+        type: "object",
+        properties: {
+          groups: {
+            type: "array",
+            items: {
+              type: "array",
+              items: {
+                type: "string",
+              },
+            },
+          },
+        },
+        additionalProperties: false,
+      },
+    ],
     docs: {
       url:
         "https://github.com/lydell/eslint-plugin-simple-import-sort#sort-order",
@@ -16,10 +44,14 @@ module.exports = {
     },
   },
   create: context => {
+    const { groups: rawGroups = defaultGroups } = context.options[0] || {};
+    const outerGroups = rawGroups.map(groups =>
+      groups.map(item => RegExp(item, "u"))
+    );
     return {
       Program: node => {
         for (const imports of extractImportChunks(node)) {
-          maybeReportSorting(imports, context);
+          maybeReportSorting(imports, context, outerGroups);
         }
       },
     };
@@ -48,10 +80,10 @@ function extractImportChunks(programNode) {
   return chunks;
 }
 
-function maybeReportSorting(imports, context) {
+function maybeReportSorting(imports, context, outerGroups) {
   const sourceCode = context.getSourceCode();
   const items = getImportItems(imports, sourceCode);
-  const sorted = printSortedImports(items, sourceCode);
+  const sorted = printSortedImports(items, sourceCode, outerGroups);
 
   const { start } = items[0];
   const { end } = items[items.length - 1];
@@ -69,42 +101,54 @@ function maybeReportSorting(imports, context) {
   }
 }
 
-function printSortedImports(importItems, sourceCode) {
-  const sideEffectImports = [];
-  const packageImports = [];
-  const relativeImports = [];
-  const restImports = [];
+function printSortedImports(importItems, sourceCode, outerGroups) {
+  const itemGroups = outerGroups.map(groups =>
+    groups.map(regex => ({ regex, items: [] }))
+  );
+  const rest = [];
 
   for (const item of importItems) {
-    if (item.group === "sideEffect") {
-      sideEffectImports.push(item);
-    } else if (item.group === "package") {
-      packageImports.push(item);
-    } else if (item.group === "relative") {
-      relativeImports.push(item);
+    const { originalSource } = item.source;
+    const source = item.isSideEffectImport
+      ? `\0${originalSource}`
+      : originalSource;
+    const [matchedGroup] = flatMap(itemGroups, groups =>
+      groups.map(group => [group, group.regex.exec(source)])
+    ).reduce(
+      ([group, longestMatch], [nextGroup, nextMatch]) =>
+        nextMatch != null &&
+        (longestMatch == null || nextMatch[0].length > longestMatch[0].length)
+          ? [nextGroup, nextMatch]
+          : [group, longestMatch],
+      [undefined, undefined]
+    );
+    if (matchedGroup == null) {
+      rest.push(item);
     } else {
-      restImports.push(item);
+      matchedGroup.items.push(item);
     }
   }
 
-  const sortedItems = [
-    sideEffectImports,
-    sortImportItems(packageImports),
-    sortImportItems(restImports),
-    sortImportItems(relativeImports),
-  ];
+  const sortedItems = itemGroups
+    .concat([[{ regex: /^/, items: rest }]])
+    .map(groups => groups.filter(group => group.items.length > 0))
+    .filter(groups => groups.length > 0)
+    .map(groups => groups.map(group => sortImportItems(group.items)));
 
   const newline = guessNewline(sourceCode);
 
   const sorted = sortedItems
-    .filter(items => items.length > 0)
-    .map(items => items.map(item => item.code).join(newline))
+    .map(groups =>
+      groups
+        .map(groupItems => groupItems.map(item => item.code).join(newline))
+        .join(newline)
+    )
     .join(newline + newline);
 
   // Edge case: If the last import (after sorting) ends with a line comment and
   // there’s code (or a multiline block comment) on the same line, add a newline
   // so we don’t accidentally comment stuff out.
-  const flattened = [].concat(...sortedItems);
+  const flattened = flatMap(sortedItems, groups => [].concat(...groups));
   const lastSortedItem = flattened[flattened.length - 1];
   const lastOriginalItem = importItems[importItems.length - 1];
   const nextToken = lastSortedItem.needsNewline
@@ -192,14 +236,14 @@ function getImportItems(passedImports, sourceCode) {
     const [start] = all[0].range;
     const [, end] = all[all.length - 1].range;
 
-    const { group, source } = getGroupAndSource(importNode, sourceCode);
+    const source = getSource(importNode);
 
     return {
       node: importNode,
       code,
       start: start - indentation.length,
       end: end + trailingSpaces.length,
-      group,
+      isSideEffectImport: isSideEffectImport(importNode, sourceCode),
       source,
       index: importIndex,
       needsNewline:
@@ -729,21 +773,21 @@ function getTrailingSpaces(node, sourceCode) {
 }
 
 function sortImportItems(items) {
-  return items.slice().sort(
-    (itemA, itemB) =>
-      // First compare the `from` part, excluding webpack loader syntax.
-      compare(itemA.source.source, itemB.source.source) ||
-      // The `.source` has been slightly tweaked. To stay fully deterministic,
-      // also sort on the original value.
-      compare(itemA.source.originalSource, itemB.source.originalSource) ||
-      // Then put Flow type imports before regular ones.
-      compare(itemA.source.importKind, itemB.source.importKind) ||
-      // Then sort by webpack loader syntax (no loaders comes first).
-      compare(itemA.source.webpack, itemB.source.webpack) ||
-      // Keep the original order if the sources are the same. It's not worth
-      // trying to compare anything else, and you can use `import/no-duplicates`
-      // to get rid of the problem anyway.
-      itemA.index - itemB.index
+  return items.slice().sort((itemA, itemB) =>
+    // If both items are side effect imports, keep their original order.
+    itemA.isSideEffectImport && itemB.isSideEffectImport
+      ? 0
+      : // First compare the `from` part.
+        compare(itemA.source.source, itemB.source.source) ||
+        // The `.source` has been slightly tweaked. To stay fully deterministic,
+        // also sort on the original value.
+        compare(itemA.source.originalSource, itemB.source.originalSource) ||
+        // Then put Flow type imports before regular ones.
+        compare(itemA.source.importKind, itemB.source.importKind) ||
+        // Keep the original order if the sources are the same. It's not worth
+        // trying to compare anything else, and you can use `import/no-duplicates`
+        // to get rid of the problem anyway.
+        itemA.index - itemB.index
   );
 }
 
@@ -795,36 +839,6 @@ function isSideEffectImport(importNode, sourceCode) {
   );
 }
 
-const PACKAGE_REGEX = /^(?:@[^/]+\/)?[^/]+/;
-
-// import fs from "fs";
-// import { compose } from "lodash/fp";
-// import { storiesOf } from '@storybook/react';
-function isPackageImport(source) {
-  const match = PACKAGE_REGEX.exec(source);
-  if (match == null) {
-    return false;
-  }
-  const { errors = [], warnings = [] } = validateNpmPackageName(match[0]);
-  return (
-    errors.length === 0 &&
-    warnings.filter(warning => !warning.includes("core module")).length === 0
-  );
-}
-
-// import a from "."
-// import a from "./x"
-// import a from ".."
-// import a from "../x"
-function isRelativeImport(source) {
-  return (
-    source === "." ||
-    source === ".." ||
-    source.startsWith("./") ||
-    source.startsWith("../")
-  );
-}
-
 function isIdentifier(node) {
   return node.type === "Identifier";
 }
@@ -849,51 +863,21 @@ function isNewline(node) {
   return node.type === "Newline";
 }
 
-// Parse the `from` part of an import, stripping away webpack loader syntax:
-//
-//     import x from "webpack-loader!./index.js"
-//                                   ^^^^^^^^^^
-// Loader syntax documentation: https://webpack.js.org/concepts/loaders/#inline
-function getGroupAndSource(importNode, sourceCode) {
-  const rawSource = importNode.source.value;
-  const index = rawSource.lastIndexOf("!");
-  const [source, webpack] =
-    index >= 0
-      ? [rawSource.slice(index + 1), rawSource.slice(0, index + 1)]
-      : [rawSource, ""];
-  const group = isSideEffectImport(importNode, sourceCode)
-    ? "sideEffect"
-    : isPackageImport(source)
-    ? "package"
-    : isRelativeImport(source)
-    ? "relative"
-    : "rest";
+function getSource(importNode) {
+  const source = importNode.source.value;
 
   return {
-    group,
-    source: {
-      source:
-        group === "relative"
-          ? // Due to "." sorting before "/" by default, relative imports are
-            // automatically sorted in a logical manner for us: Imports from files
-            // further up come first, with deeper imports last. There’s one
-            // exception, though: When the `from` part ends with one or two dots:
-            // "." and "..". Those are supposed to sort just like "./", "../". So
-            // add in the slash for them. (No special handling is done for cases
-            // like "./a/.." because nobody writes that anyway.)
-            source === "." || source === ".."
-            ? `${source}/`
-            : source
-          : group === "rest"
-          ? // This makes ASCII letters and digits sort first. When using
-            // `Intl.Collator`, `\t` followed by a letter sorts first (while `\0`
-            // followed by a letter comes a lot later!).
-            source.replace(/^[a-z\d]/i, "\t$&")
-          : source,
-      originalSource: source,
-      importKind: getImportKind(importNode),
-      webpack,
-    },
+    source:
+      // Due to "." sorting before "/" by default, relative imports are
+      // automatically sorted in a logical manner for us: Imports from files
+      // further up come first, with deeper imports last. There’s one
+      // exception, though: When the `from` part ends with one or two dots:
+      // "." and "..". Those are supposed to sort just like "./", "../". So
+      // add in the slash for them. (No special handling is done for cases
+      // like "./a/.." because nobody writes that anyway.)
+      source === "." || source === ".." ? `${source}/` : source,
+    originalSource: source,
+    importKind: getImportKind(importNode),
   };
 }
 
diff --git a/test/__snapshots__/examples.test.js.snap b/test/__snapshots__/examples.test.js.snap
index d8a9aac..7cd999d 100644
--- a/test/__snapshots__/examples.test.js.snap
+++ b/test/__snapshots__/examples.test.js.snap
@@ -65,6 +65,63 @@ bar();
 
 `;
 
+exports[`examples groups.custom.js 1`] = `
+import assert from "assert";
+import fs from "fs";
+
+import react from "react";
+import Select from "react-select"
+import _ from "lodash"
+
+import Textarea from "@/ui/Textarea"
+import {name} from "@company/config"
+import Button from "@ui/Button";
+import Label from "components/Label"
+import {API_URL} from "config";
+import {pluralize} from "utils/string"
+import VendoredLib from "vendored-lib"
+import createWrapper from "vendored-lib/lib/create-wrapper"
+
+import "./local-polyfill"
+import "polyfill-package"
+
+import cssGlobals from "../../css/globals"
+import {removeWhitespace,truncate} from "../../utils";
+import {CATEGORIES} from "../"
+
+import now from "./time/now"
+import tomorrow from "./time/tomorrow"
+import {providers} from "./providers"
+import {PRODUCT_NAMES} from "."
+
+import circleSyles from "./circle.scss";
+import "./global.scss"
+import "../../alert.css"
+import styles from "./styles.scss";
+
+`;
+
+exports[`examples groups.no-blank-lines.js 1`] = `
+import classnames from "classnames";
+import PropTypes from "prop-types";
+import React from "react";
+import { getUser } from "../../api";
+import { User } from "../../types";
+import { formatNumber,truncate } from "../../utils";
+import Button from "../Button";
+import styles from "./styles.css";
+
+`;
+
+exports[`examples groups.none.js 1`] = `
+import styles from "./styles";
+import App from "@/App";
+import { storiesOf } from "@storybook/react";
+import config from "/config";
+import react from "react";
+
+`;
+
 exports[`examples ignore.js 1`] = `
 // First off, imports that are only used for side effects stay in the input
 // order. These won’t be sorted:
@@ -213,9 +270,9 @@ import "./global.css";
 import type A from "an-npm-package";
 import a from "an-npm-package";
 import fs from "fs";
-
-// Absolute imports, full URLs and other imports.
 import b from "https://example.com/script.js";
+
+// Absolute imports and other imports.
 import Error from "@/components/error.vue";
 import c from "/";
 import d from "/home/user/foo";
@@ -228,7 +285,6 @@ import typeof C from "../types";
 import g from ".";
 import h from "./constants";
 import i from "./styles";
-import j from "html-loader!./text.html";
 // Regardless of group, imported items are sorted like this:
 import {
   // First, Flow type imports.
diff --git a/test/sort.test.js b/test/sort.test.js
index 618d3c3..1d5174a 100644
--- a/test/sort.test.js
+++ b/test/sort.test.js
@@ -818,39 +818,11 @@ const baseTests = expect => ({
       errors: 1,
     },
 
-    // Webpack loader syntax
-    {
-      code: input`
-          |import x1 from "webpack-loader!b"
-          |import x2 from "webpack-loader!./c"
-          |import x3 from "webpack-loader!/d"
-          |import x4 from 'loader1!loader2?query!loader3?{"key":"value!"}!a'
-          |import x5 from "webpack-loader!b"
-          |import x6 from "other-loader!b"
-          |import x7 from "b"
-      `,
-      output: actual => {
-        expect(actual).toMatchInlineSnapshot(`
-          |import x4 from 'loader1!loader2?query!loader3?{"key":"value!"}!a'
-          |import x7 from "b"
-          |import x6 from "other-loader!b"
-          |import x1 from "webpack-loader!b"
-          |import x5 from "webpack-loader!b"
-          |
-          |import x3 from "webpack-loader!/d"
-          |
-          |import x2 from "webpack-loader!./c"
-        `);
-      },
-      errors: 1,
-    },
-
     // Special characters sorting order.
     {
       code: input`
           |import {} from "";
           |import {} from ".";
-          |import {} from "loader!.";
           |import {} from ".//";
           |import {} from "./";
           |import {} from "./B"; // B1
@@ -905,21 +877,17 @@ const baseTests = expect => ({
           |import {} from "@storybook/react";
           |import {} from "@storybook/react/something";
           |import {} from "1";
+          |import {} from "1*";
+          |import {} from "a*";
           |import {} from "async";
+          |import {} from "Fs";
           |import {} from "fs";
           |import {} from "fs/something";
+          |import {} from "http://example.com/script.js";
+          |import {} from "https://example.com/script.js";
           |import {} from "lodash/fp";
           |import {} from "react";
           |
-          |import {} from "";
-          |import {} from "1*";
-          |import {} from "a*";
-          |import {} from "Fs";
-          |import {} from "http://example.com/script.js";
-          |import {} from "https://example.com/script.js";
-          |import {} from "...";
-          |import {} from ".../";
-          |import {} from ".a";
           |import {} from "@/components/Alert"
           |import {} from "@/components/error.vue"
           |import {} from "/";
@@ -928,6 +896,8 @@ const baseTests = expect => ({
           |import {} from "#/test"
           |import {} from "~/test"
           |
+          |import {} from "...";
+          |import {} from ".../";
           |import {} from "..";
           |import {} from "../";
           |import {} from "../..";
@@ -939,7 +909,6 @@ const baseTests = expect => ({
           |import {} from "../a/../";
           |import {} from "../a/../b";
           |import {} from ".";
-          |import {} from "loader!.";
           |import {} from "./";
           |import {} from ".//";
           |import {} from "./A";
@@ -955,6 +924,9 @@ const baseTests = expect => ({
           |import img1 from "./img1";
           |import img2 from "./img2";
           |import img10 from "./img10";
+          |import {} from ".a";
+          |
+          |import {} from "";
         `);
       },
       errors: 1,
@@ -1082,7 +1054,7 @@ const baseTests = expect => ({
           |// a
           |
           |import a from "a"
-`,
+      `,
       output: actual => {
         expect(actual).toMatchInlineSnapshot(`
           |// a
@@ -1108,7 +1080,7 @@ const baseTests = expect => ({
           |\r
           |import a from "a"\r
           |after();\r
-`,
+      `,
       output: actual => {
         expect(actual).toMatchInlineSnapshot(`
           |// a<CR>
@@ -1181,7 +1153,7 @@ const baseTests = expect => ({
           |// final
           |
           |;
-`,
+      `,
       output: actual => {
         expect(actual).toMatchInlineSnapshot(`
           |import
@@ -1224,7 +1196,7 @@ const baseTests = expect => ({
           |import {
           |
           |    } from "specifiers-empty"
-`,
+      `,
       output: actual => {
         expect(actual).toMatchInlineSnapshot(`
           |import {
@@ -1242,7 +1214,7 @@ const baseTests = expect => ({
           |
           |  b // b
           |  ,a} from "specifiers-line-comment"
-`,
+      `,
       output: actual => {
         expect(actual).toMatchInlineSnapshot(`
           |import {
@@ -1266,7 +1238,7 @@ const baseTests = expect => ({
           |  
           |    // d
           |    import d from "d"
-`,
+      `,
       output: actual => {
         expect(actual).toMatchInlineSnapshot(`
           |  /* a */ import a from "a"; 
@@ -1299,7 +1271,7 @@ const baseTests = expect => ({
           |    // d\r
           |    import d from "d"\r
           |
-`,
+      `,
       output: actual => {
         expect(actual).toMatchInlineSnapshot(`
           |      <CR>
@@ -1459,6 +1431,141 @@ const baseTests = expect => ({
       },
       errors: 1,
     },
+
+    // `groups` – `u` flag.
+    {
+      options: [{ groups: [["^\\p{L}"], ["^\\."]] }],
+      code: input`
+          |import b from '.';
+          |import a from 'ä';
+      `,
+      output: actual => {
+        expect(actual).toMatchInlineSnapshot(`
+          |import a from 'ä';
+          |
+          |import b from '.';
+        `);
+      },
+      errors: 1,
+    },
+
+    // `groups` – non-matching imports end up last.
+    {
+      options: [{ groups: [["^\\w"], ["^\\."]] }],
+      code: input`
+          |import c from '';
+          |import b from '.';
+          |import a from 'a';
+          |import d from '@/a';
+      `,
+      output: actual => {
+        expect(actual).toMatchInlineSnapshot(`
+          |import a from 'a';
+          |
+          |import b from '.';
+          |
+          |import c from '';
+          |import d from '@/a';
+        `);
+      },
+      errors: 1,
+    },
+
+    // `groups` – first longest match wins.
+    {
+      options: [{ groups: [["^\\w"], ["^\\w{2}"], ["^.{2}"]] }],
+      code: input`
+          |import c from './';
+          |import b from 'bx';
+          |import a from 'a';
+      `,
+      output: actual => {
+        expect(actual).toMatchInlineSnapshot(`
+          |import a from 'a';
+          |
+          |import b from 'bx';
+          |
+          |import c from './';
+        `);
+      },
+      errors: 1,
+    },
+
+    // `groups` – side effect imports.
+    {
+      options: [{ groups: [["^\\w"], ["^\\."], ["^\\u0000"]] }],
+      code: input`
+          |import '@/';
+          |import c from '@/';
+          |import b from './';
+          |import './';
+          |import a from 'a';
+          |import 'a';
+          |import {} from 'a';
+      `,
+      output: actual => {
+        expect(actual).toMatchInlineSnapshot(`
+          |import a from 'a';
+          |import {} from 'a';
+          |
+          |import b from './';
+          |
+          |import '@/';
+          |import './';
+          |import 'a';
+          |
+          |import c from '@/';
+        `);
+      },
+      errors: 1,
+    },
+
+    // `groups` – side effect imports keep internal order but are sorted otherwise.
+    {
+      options: [{ groups: [] }],
+      code: input`
+          |import b from 'b';
+          |import 'c';
+          |import d from 'd';
+          |import 'a';
+          |import '.';
+          |import x from './x';
+      `,
+      output: actual => {
+        expect(actual).toMatchInlineSnapshot(`
+          |import x from './x';
+          |import b from 'b';
+          |import 'c';
+          |import 'a';
+          |import '.';
+          |import d from 'd';
+        `);
+      },
+      errors: 1,
+    },
+
+    // `groups` – no line breaks between inner array items.
+    {
+      options: [{ groups: [["^\\w", "^react"], ["^\\."]] }],
+      code: input`
+          |import react from 'react';
+          |import a from 'a';
+          |import webpack from "webpack"
+          |import Select from 'react-select';
+          |import App from './App';
+      `,
+      output: actual => {
+        expect(actual).toMatchInlineSnapshot(`
+          |import a from 'a';
+          |import webpack from "webpack"
+          |import react from 'react';
+          |import Select from 'react-select';
+          |
+          |import App from './App';
+        `);
+      },
+      errors: 1,
+    },
   ],
 });
 
@@ -1515,11 +1622,11 @@ const flowTests = {
         expect(actual).toMatchInlineSnapshot(`
           |import './global.css';
           |
-          |import react from "react"
-          |
           |import typeof A from "A";
+          |import react from "react"
           |import type {X} from "X";
           |import type {Z} from "Z";
+          |
           |import type E from "@/B";
           |import type C from "/B";
           |
@@ -1531,36 +1638,6 @@ const flowTests = {
       errors: 1,
     },
 
-    // All at once.
-    {
-      code: input`
-          |import A from "webpack!a";
-          |import B from "webpack!./a";
-          |import type C from "a";
-          |import D from "a";
-          |import typeof E from "a";
-          |import type F from "flow!./a";
-          |import type G from "flow!a";
-          |import typeof H from "a";
-          |import type I from "./a";
-      `,
-      output: actual => {
-        expect(actual).toMatchInlineSnapshot(`
-          |import type C from "a";
-          |import type G from "flow!a";
-          |import typeof E from "a";
-          |import typeof H from "a";
-          |import D from "a";
-          |import A from "webpack!a";
-          |
-          |import type I from "./a";
-          |import type F from "flow!./a";
-          |import B from "webpack!./a";
-        `);
-      },
-      errors: 1,
-    },
-
     // https://github.com/graphql/graphql-js/blob/64b194c6c9b9aaa1c139f1b7c3692a6ef851928e/src/execution/execute.js#L10-L69
     {
       code: input`