lib/path: Fix @go.canonicalize_path bugs, add @go.add_parent_dir_if_relative_path

lib/path

@@ -6,6 +6,9 @@
 #   @go.canonicalize_path
 #     Removes all extra slashes from a path and resolves all relative components
 #
+#   @go.add_parent_dir_if_relative_path
+#     Adds a parent dir to a relative path
+#
 #   @go.walk_file_system
 #     Performs an operation on file system objects and recurses into directories
 #
@@ -27,12 +30,17 @@
 #   path:              Path to canonicalize
 @go.canonicalize_path() {
   @go.validate_identifier_or_die 'Canonicalized path result variable' "$1"
-  printf -v "$1" '%s' "$2/"
+
+  printf -v "$1" '%s' "${2}${2:+/}"
 
   while [[ "${!1}" =~ //+ ]]; do
     printf -v "$1" '%s' "${!1/"${BASH_REMATCH[0]}"//}"
   done
 
+  while [[ "${!1}" =~ ^\./. ]]; do
+    printf -v "$1" '%s' "${!1#./}"
+  done
+
   while [[ "${!1}" =~ /\./ ]]; do
     printf -v "$1" '%s' "${!1/"${BASH_REMATCH[0]}"//}"
   done
@@ -56,6 +64,32 @@
   fi
 }
 
+# Adds a parent dir to a relative path
+#
+# If the path is absolute, the original path is assigned.
+#
+# Options:
+#   --parent:  Parent dir to add to `path` (default `PWD`)
+#
+# Arguments:
+#   result_var_name:   Name of the variable into which the result will be stored
+#   path:              Path to make absolute if it's relative
+@go.add_parent_dir_if_relative_path() {
+  local __gapdirp_parent="$PWD"
+
+  if [[ "$1" == '--parent' ]]; then
+    __gapdirp_parent="$2"
+    shift 2
+  fi
+  @go.validate_identifier_or_die 'Absolute path result variable' "$1"
+
+  if [[ "${2:0:1}" != '/' ]]; then
+    printf -v "$1" '%s/%s' "$__gapdirp_parent" "$2"
+  else
+    printf -v "$1" '%s' "$2"
+  fi
+}
+
 # Performs an operation on file system objects and recurses into directories
 #
 # Each call to `operation` receives a path to an existing file system object.
@@ -78,7 +112,7 @@
 #   Nonzero if the algorithm was terminated by a nonzero return from `operation`
 @go.walk_file_system() {
   local operation
-  local current 
+  local current
   local do_bfs
   local bfs_queue=()
 

tests/path-module/add-parent-dir-if-relative-path.bats

@@ -0,0 +1,31 @@
+#! /usr/bin/env bats
+
+load ../environment
+
+setup() {
+  test_filter
+  @go.create_test_go_script \
+    '. "$_GO_USE_MODULES" "path"' \
+    'declare result' \
+    '@go.add_parent_dir_if_relative_path "$@"' \
+    'printf "%s\n" "$result"'
+}
+
+teardown() {
+  @go.remove_test_go_rootdir
+}
+
+@test "$SUITE: converts a relative path to an absolute path based on PWD" {
+  run "$TEST_GO_SCRIPT" 'result' 'foo'
+  assert_success "$TEST_GO_ROOTDIR/foo"
+}
+
+@test "$SUITE: adds a parent to a relative path" {
+  run "$TEST_GO_SCRIPT" --parent 'foo' 'result' 'bar'
+  assert_success 'foo/bar'
+}
+
+@test "$SUITE: leaves an absolute path unmodified" {
+  run "$TEST_GO_SCRIPT" --parent 'foo' 'result' '/bar/baz'
+  assert_success '/bar/baz'
+}

tests/path-module/canonicalize-path.bats

@@ -24,6 +24,11 @@ run_canonicalize_path() {
   assert_success '/foo/bar/baz'
 }
 
+@test "$SUITE: leaves the empty path unchanged" {
+  run_canonicalize_path ''
+  assert_success ''
+}
+
 @test "$SUITE: leaves root path unchanged" {
   run_canonicalize_path '/'
   assert_success '/'
@@ -84,8 +89,23 @@ run_canonicalize_path() {
   assert_success 'foo/bar/baz'
 }
 
+@test "$SUITE: resolves a leading relative self" {
+  run_canonicalize_path './foo/bar/baz'
+  assert_success 'foo/bar/baz'
+}
+
+@test "$SUITE: resolves a leading relative self before '..'" {
+  run_canonicalize_path './..'
+  assert_success '..'
+}
+
+@test "$SUITE: resolves a trailing relative self" {
+  run_canonicalize_path 'foo/bar/baz/.'
+  assert_success 'foo/bar/baz'
+}
+
 @test "$SUITE: resolves multiple relative selves" {
-  run_canonicalize_path 'foo/./bar/././baz/./././'
+  run_canonicalize_path 'foo/./bar/././baz/././.'
   assert_success 'foo/bar/baz'
 }