feat: support 'replace' string helper

book/src/stubs/index.md

@@ -99,6 +99,7 @@ You will find here in a single snippet **ALL** the fields/helpers available to y
       "number-is-odd": "{{isOdd 3}}", // or 'isEven'
       "string-capitalized": "{{capitalize mister}}", // or 'decapitalize'
       "string-uppercase": "{{upper mister}}", // or 'lower'
+      "string-replace": "{{replace request.body 'a' 'b'}}", // e.g. given "Handlebars" in request body returns "Hbndlebbrs"
       "number-stripes": "{{stripes request.body 'if-even' 'if-odd'}}",
       "string-trim": "{{trim request.body}}", // removes leading & trailing whitespaces
       "size": "{{size request.body}}", // string length or array length

book/src/stubs/response.md

@@ -193,6 +193,7 @@ You also sometimes have to generate dynamic data or to transform existing one:
       "number-stripes": "{{stripes request.body 'if-even' 'if-odd'}}",
       "string-capitalized": "{{capitalize request.body}}",
       "string-uppercase": "{{upper request.body}}",
+      "string-replace": "{{replace request.body 'a' 'b'}}",
       "string-trim": "{{trim request.body}}",
       "size": "{{size request.body}}",
       "base64-encode": "{{base64 request.body padding=false}}",
@@ -217,8 +218,11 @@ You also sometimes have to generate dynamic data or to transform existing one:
     * `timezone` for using a string timezone (
       see [list](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones#List))
 * `isOdd` or `isEven` returns a boolean whether the numeric value is an even or odd integer
-* `capitalize` first letter to uppercase e.g. `mister` becomes `Mister`
+* `capitalize` first letter to uppercase e.g. `mister` becomes `Mister`. There's also a `decapitalize` to do the
+  opposite.
 * `upper` or `lower` recapitalizes the whole word
+* `replace` for replacing a pattern with given input e.g. `{{replace request.body 'a' 'b'}}` will replace all the `a` in
+  the request body with `b`
 * `stripes` returns alternate values depending if the tested value is even or odd
 * `trim` removes leading & trailing whitespaces
 * `size` returns the number of bytes for a string (⚠️ not the number of characters) or the size of an array

lib/src/model/response/template/helpers/any/mod.rs

@@ -1,7 +1,7 @@
 use crate::StubrResult;
 use handlebars::{Context, Helper, Output, RenderContext, RenderError};
 
-use super::{super::verify::Verifiable, utils_str::ValueExt, verify::VerifyDetect};
+use super::{super::verify::Verifiable, verify::VerifyDetect, ValueExt};
 
 pub mod alpha_numeric;
 pub mod boolean;

lib/src/model/response/template/helpers/any/of.rs

@@ -2,7 +2,7 @@ use handlebars::{Context, Handlebars, Helper, HelperDef, HelperResult, Output, P
 use itertools::Itertools;
 use rand::prelude::IteratorRandom;
 
-use crate::{model::response::template::helpers::utils_str::ValueExt, StubrError, StubrResult};
+use crate::{model::response::template::helpers::ValueExt, StubrError, StubrResult};
 
 use super::{super::verify::VerifyDetect, AnyTemplate};
 

lib/src/model/response/template/helpers/any/regex.rs

@@ -5,7 +5,7 @@ use crate::gen::regex::RegexRndGenerator;
 use crate::{StubrError, StubrResult};
 
 use super::{
-    super::{utils_str::ValueExt, verify::VerifyDetect},
+    super::{verify::VerifyDetect, ValueExt},
     AnyTemplate,
 };
 

lib/src/model/response/template/helpers/base64.rs

@@ -3,7 +3,7 @@ use std::str::from_utf8;
 use handlebars::{Context, Handlebars, Helper, HelperDef, HelperResult, Output, PathAndJson, RenderContext, RenderError};
 use serde_json::Value;
 
-use super::utils_str::ValueExt;
+use super::ValueExt;
 
 pub struct Base64Helper;
 

lib/src/model/response/template/helpers/datetime.rs

@@ -1,13 +1,12 @@
 use std::time::{SystemTime, UNIX_EPOCH};
 
+use super::HelperExt;
 use chrono::{prelude::*, Duration};
 use chrono_tz::Tz;
 use handlebars::{Context, Handlebars, Helper, HelperDef, RenderContext, RenderError, ScopedJson};
 use humantime::parse_duration;
 use serde_json::Value;
 
-use super::utils_str::ValueExt;
-
 pub struct NowHelper;
 
 impl NowHelper {
@@ -23,7 +22,7 @@ impl NowHelper {
     }
 
     fn fmt_with_custom_format(now: DateTime<Utc>, h: &Helper) -> Option<String> {
-        if let Some(format) = Self::get_hash(h, Self::FORMAT) {
+        if let Some(format) = h.get_str_hash(Self::FORMAT) {
             match format {
                 Self::EPOCH => SystemTime::now()
                     .duration_since(UNIX_EPOCH)
@@ -40,12 +39,8 @@ impl NowHelper {
         }
     }
 
-    fn get_hash<'a>(h: &'a Helper, key: &str) -> Option<&'a str> {
-        h.hash_get(key)?.relative_path().map(String::escape_single_quotes)
-    }
-
     fn apply_offset(now: DateTime<Utc>, h: &Helper) -> DateTime<Utc> {
-        Self::get_hash(h, Self::OFFSET)
+        h.get_str_hash(Self::OFFSET)
             .map(|it| it.replace(' ', ""))
             .and_then(|offset| Self::compute_offset(now, offset))
             .unwrap_or(now)
@@ -65,7 +60,7 @@ impl NowHelper {
     }
 
     fn apply_timezone(now: DateTime<Utc>, h: &Helper) -> DateTime<Utc> {
-        Self::get_hash(h, Self::TIMEZONE)
+        h.get_str_hash(Self::TIMEZONE)
             .and_then(|timezone| timezone.parse().ok())
             .map(|tz: Tz| tz.offset_from_utc_datetime(&now.naive_utc()).fix().local_minus_utc())
             .map(i64::from)

lib/src/model/response/template/helpers/mod.rs

@@ -5,7 +5,40 @@ pub mod json_path;
 pub mod numbers;
 pub mod size;
 pub mod string;
+pub mod string_replace;
 pub mod trim;
 pub mod url_encode;
-pub mod utils_str;
 pub mod verify;
+
+trait HelperExt {
+    fn get_str_hash(&self, key: &str) -> Option<&str>;
+    fn get_first_str_value(&self) -> Option<&str>;
+}
+
+impl HelperExt for handlebars::Helper<'_, '_> {
+    fn get_str_hash(&self, key: &str) -> Option<&str> {
+        self.hash_get(key)?.relative_path().map(String::escape_single_quotes)
+    }
+
+    fn get_first_str_value(&self) -> Option<&str> {
+        self.param(0)?.value().as_str()
+    }
+}
+
+pub trait ValueExt {
+    const QUOTE: char = '\'';
+
+    fn escape_single_quotes(&self) -> &str;
+}
+
+impl ValueExt for String {
+    fn escape_single_quotes(&self) -> &str {
+        self.trim_start_matches(Self::QUOTE).trim_end_matches(Self::QUOTE)
+    }
+}
+
+impl ValueExt for str {
+    fn escape_single_quotes(&self) -> &str {
+        self.trim_start_matches(Self::QUOTE).trim_end_matches(Self::QUOTE)
+    }
+}

lib/src/model/response/template/helpers/numbers.rs

@@ -3,7 +3,7 @@ use std::ops::Not;
 use handlebars::{Context, Handlebars, Helper, HelperDef, RenderContext, RenderError, ScopedJson};
 use serde_json::Value;
 
-use super::utils_str::ValueExt;
+use super::ValueExt;
 
 pub struct NumberHelper;
 

lib/src/model/response/template/helpers/string.rs

@@ -1,3 +1,4 @@
+use crate::model::response::template::helpers::HelperExt;
 use handlebars::{Context, Handlebars, Helper, HelperDef, RenderContext, RenderError, ScopedJson};
 use serde_json::Value;
 
@@ -9,10 +10,6 @@ impl StringHelper {
     pub const UPPER: &'static str = "upper";
     pub const LOWER: &'static str = "lower";
 
-    fn value<'a>(h: &'a Helper) -> Option<&'a str> {
-        h.params().get(0)?.value().as_str()
-    }
-
     fn capitalize(value: &str) -> String {
         Self::map_first(value, char::to_ascii_uppercase)
     }
@@ -33,14 +30,15 @@ impl HelperDef for StringHelper {
     fn call_inner<'reg: 'rc, 'rc>(
         &self, h: &Helper<'reg, 'rc>, _: &'reg Handlebars<'reg>, _: &'rc Context, _: &mut RenderContext<'reg, 'rc>,
     ) -> Result<ScopedJson<'reg, 'rc>, RenderError> {
-        Self::value(h)
+        h.get_first_str_value()
             .map(|value| match h.name() {
-                Self::UPPER => value.to_uppercase(),
-                Self::LOWER => value.to_lowercase(),
-                Self::CAPITALIZE => Self::capitalize(value),
-                Self::DECAPITALIZE => Self::decapitalize(value),
-                _ => panic!("Unexpected error"),
+                Self::UPPER => Ok(value.to_uppercase()),
+                Self::LOWER => Ok(value.to_lowercase()),
+                Self::CAPITALIZE => Ok(Self::capitalize(value)),
+                Self::DECAPITALIZE => Ok(Self::decapitalize(value)),
+                _ => Err(RenderError::new("Unsupported string helper")),
             })
+            .transpose()?
             .ok_or_else(|| RenderError::new("Invalid string case transform response template"))
             .map(Value::from)
             .map(ScopedJson::from)

lib/src/model/response/template/helpers/string_replace.rs

@@ -0,0 +1,30 @@
+use super::ValueExt;
+use crate::model::response::template::helpers::HelperExt;
+use handlebars::{Context, Handlebars, Helper, HelperDef, RenderContext, RenderError, ScopedJson};
+use serde_json::Value;
+
+pub struct StringReplaceHelper;
+
+impl StringReplaceHelper {
+    pub const REPLACE: &'static str = "replace";
+}
+
+impl HelperDef for StringReplaceHelper {
+    fn call_inner<'reg: 'rc, 'rc>(
+        &self, h: &Helper<'reg, 'rc>, _: &'reg Handlebars<'reg>, _: &'rc Context, _: &mut RenderContext<'reg, 'rc>,
+    ) -> Result<ScopedJson<'reg, 'rc>, RenderError> {
+        let value = h.get_first_str_value().ok_or(RenderError::new(
+            "Missing value after 'replace' helper e.g. {{replace request.body ...}}",
+        ))?;
+        let (placeholder, replacer) = h
+            .param(1)
+            .zip(h.param(2))
+            .and_then(|(p, r)| p.relative_path().zip(r.relative_path()))
+            .map(|(p, r)| (p.escape_single_quotes(), r.escape_single_quotes()))
+            .ok_or(RenderError::new(
+                "Missing values after 'replace' helper e.g. {{replace request.body 'apple' 'peach'}}",
+            ))?;
+        let replaced = value.replace(placeholder, replacer);
+        Ok(Value::from(replaced).into())
+    }
+}

lib/src/model/response/template/helpers/trim.rs

@@ -1,21 +1,18 @@
+use crate::model::response::template::helpers::HelperExt;
 use handlebars::{Context, Handlebars, Helper, HelperDef, RenderContext, RenderError, ScopedJson};
 use serde_json::Value;
 
 pub struct TrimHelper;
 
 impl TrimHelper {
     pub const NAME: &'static str = "trim";
-
-    fn value<'a>(h: &'a Helper) -> Option<&'a str> {
-        h.params().get(0)?.value().as_str()
-    }
 }
 
 impl HelperDef for TrimHelper {
     fn call_inner<'reg: 'rc, 'rc>(
         &self, h: &Helper<'reg, 'rc>, _: &'reg Handlebars<'reg>, _: &'rc Context, _: &mut RenderContext<'reg, 'rc>,
     ) -> Result<ScopedJson<'reg, 'rc>, RenderError> {
-        Self::value(h)
+        h.get_first_str_value()
             .ok_or_else(|| RenderError::new("Invalid trim response template"))
             .map(str::trim)
             .map(Value::from)

lib/src/model/response/template/helpers/url_encode.rs

@@ -2,7 +2,7 @@ use handlebars::{Context, Handlebars, Helper, HelperDef, PathAndJson, RenderCont
 use percent_encoding::{percent_decode_str, utf8_percent_encode, NON_ALPHANUMERIC};
 use serde_json::Value;
 
-use super::utils_str::ValueExt;
+use super::ValueExt;
 
 pub struct UrlEncodingHelper;
 

lib/src/model/response/template/mod.rs

@@ -22,6 +22,7 @@ use helpers::{
     numbers::NumberHelper,
     size::SizeHelper,
     string::StringHelper,
+    string_replace::StringReplaceHelper,
     trim::TrimHelper,
     url_encode::UrlEncodingHelper,
 };
@@ -47,6 +48,7 @@ lazy_static! {
         handlebars.register_helper(StringHelper::DECAPITALIZE, Box::new(StringHelper));
         handlebars.register_helper(StringHelper::UPPER, Box::new(StringHelper));
         handlebars.register_helper(StringHelper::LOWER, Box::new(StringHelper));
+        handlebars.register_helper(StringReplaceHelper::REPLACE, Box::new(StringReplaceHelper));
         handlebars.register_helper(SizeHelper::NAME, Box::new(SizeHelper));
         handlebars.register_helper(AnyRegex::NAME, Box::new(AnyRegex));
         handlebars.register_helper(AnyNonBlank::NAME, Box::new(AnyNonBlank));

lib/tests/resp/template/string.rs

@@ -44,3 +44,14 @@ async fn should_template_lowercase() {
         .expect_body_text_eq("john")
         .expect_content_type_text();
 }
+
+#[async_std::test]
+#[stubr::mock("resp/template/string/replace.json")]
+async fn should_template_replace() {
+    post(stubr.uri())
+        .body("Handlebars")
+        .await
+        .expect_status_ok()
+        .expect_body_text_eq("Hbndlebbrs")
+        .expect_content_type_text();
+}

lib/tests/stubs/resp/template/string/replace.json

@@ -0,0 +1,12 @@
+{
+  "request": {
+    "method": "POST"
+  },
+  "response": {
+    "status": 200,
+    "body": "{{replace request.body 'a' 'b'}}",
+    "transformers": [
+      "response-template"
+    ]
+  }
+}