Extract @go.search_plugins

go-core.bash

@@ -114,7 +114,10 @@ declare -x _GO_CMD_NAME=
 # string with the arguments delimited by the ASCII Unit Separator ($'\x1f').
 declare -x _GO_CMD_ARGV=
 
-# The directory in which plugins are installed.
+# The top-level directory in which plugins are installed.
+#
+# If a command script is running as a plugin, this value will be the plugins
+# directory of the top-level `./go` script.
 declare _GO_PLUGINS_DIR=
 
 # Directories containing executable plugin scripts.
@@ -204,6 +207,52 @@ declare _GO_INJECT_MODULE_PATH="$_GO_INJECT_MODULE_PATH"
   return "$result"
 }
 
+# Searches through plugin directories using a helper function
+#
+# The search will begin in `_GO_SCRIPTS_DIR/plugins`. As long as `search_func`
+# returns nonzero, every parent `/plugins/` directory will be searched, up to
+# and including the top-level `_GO_PLUGINS_DIR`. The search will end either when
+# `search_func` returns zero, or when all of the plugin paths are exhausted.
+#
+# The helper function, `search_func`, will receive the current plugin directory
+# being searched as its sole argument. The `@go.search_plugins` caller's
+# variables will be available in its scope. It should return zero when the
+# search criteria are satisfied, nonzero if the search should continue.
+#
+# For example, to search for a particular item in a particular plugin:
+#
+# find_plugin_item() {
+#   [[ -e "$1/item_path" ]] && item_path="$1/item_path"
+# }
+#
+# my_func() {
+#   local item_path='foo/bar'
+#   if @go.search_plugins find_plugin_item; then
+#     # Do something with $item_path
+#   fi
+# }
+#
+# Arguments:
+#   search_func:  Helper function implementing the search operation
+#
+# Returns:
+#   Zero if `search_func` ever returns zero, nonzero otherwise
+@go.search_plugins() {
+  local __gsp_plugins_dir="$_GO_SCRIPTS_DIR/plugins"
+
+  # Set `_GO_PLUGINS_DIR` if called from a top-level `./go` script before `@go`.
+  _GO_PLUGINS_DIR="${_GO_PLUGINS_DIR:-$_GO_SCRIPTS_DIR/plugins}"
+
+  while true; do
+    if "$1" "$__gsp_plugins_dir"; then
+      return
+    elif [[ "$__gsp_plugins_dir" == "$_GO_PLUGINS_DIR" ]]; then
+      return 1
+    fi
+    __gsp_plugins_dir="${__gsp_plugins_dir%/plugins/*}/plugins"
+  done
+}
+
 # Main driver of ./go script functionality.
 #
 # Arguments:

lib/internal/path

@@ -1,8 +1,14 @@
 #! /bin/bash
 
+_@go.set_search_paths_add_plugin_paths() {
+  local plugin_paths=("$1"/*/bin)
+  if [[ "${plugin_paths[0]}" != "$1/*/bin" ]]; then
+    _GO_PLUGINS_PATHS+=("${plugin_paths[@]}")
+  fi
+  return 1
+}
+
 _@go.set_search_paths() {
-  local plugins_dir="$_GO_SCRIPTS_DIR/plugins"
-  local plugins_paths=()
   local plugin_path
 
   if [[ -n "$_GO_INJECT_SEARCH_PATH" ]]; then
@@ -13,21 +19,9 @@ _@go.set_search_paths() {
   # A plugin's own local plugin paths will appear before inherited ones. If
   # there is a version incompatibility issue with other installed plugins, this
   # allows a plugin's preferred version to take precedence.
-  while [[ "$plugins_dir" =~ ^$_GO_PLUGINS_DIR ]]; do
-    plugin_paths=("$plugins_dir"/*/bin)
-    if [[ "${plugin_paths[0]}" != "$plugins_dir/*/bin" ]]; then
-      _GO_PLUGINS_PATHS+=("${plugin_paths[@]}")
-    fi
-    if [[ "$plugins_dir" == "$_GO_PLUGINS_DIR" ]]; then
-      break
-    fi
-    plugins_dir="${plugins_dir%/plugins/*}/plugins"
-  done
+  @go.search_plugins '_@go.set_search_paths_add_plugin_paths'
 
-  # A plugin's _GO_SCRIPTS_DIR may continue to appear in _GO_PLUGINS_PATHS so
-  # that it's available to other plugins that depend upon it as a circular
-  # dependency (though such dependencies are strongly discouraged). However, we
-  # will ensure its _GO_SCRIPTS_DIR isn't duplicated in _GO_SEARCH_PATHS.
+  # Ensure a plugin's _GO_SCRIPTS_DIR isn't duplicated in _GO_SEARCH_PATHS.
   for plugin_path in "${_GO_PLUGINS_PATHS[@]}"; do
     if [[ "$plugin_path" != "$_GO_SCRIPTS_DIR" ]]; then
       _GO_SEARCH_PATHS+=("$plugin_path")

tests/core/search-plugins.bats

@@ -0,0 +1,152 @@
+#! /usr/bin/env bats
+
+load ../environment
+
+setup() {
+  test_filter
+  @go.create_test_go_script \
+    'collect_dirs_impl() {' \
+    '  [[ -d "$1" ]] && dirs_searched+=("$1")' \
+    '  [[ "$((--COLLECT_DIRS_SUCCESS_AFTER_NUM_ITERATIONS))" -eq "0" ]]' \
+    '}' \
+    'collect_dirs() {' \
+    '  local dirs_searched=()' \
+    '  @go.search_plugins collect_dirs_impl' \
+    '  local result="$?"' \
+    '  printf "%s\n" "${dirs_searched[@]}"' \
+    '  return "$result"' \
+    '}' \
+    'if [[ -z "$COLLECT_DIRS_SUCCESS_AFTER_NUM_ITERATIONS" ]]; then' \
+    '  COLLECT_DIRS_SUCCESS_AFTER_NUM_ITERATIONS=1' \
+    'fi' \
+    '@go "$@"'
+}
+
+teardown() {
+  @go.remove_test_go_rootdir
+}
+
+@test "$SUITE: _GO_PLUGINS_DIR doesn't exist" {
+  @go.create_test_command_script 'top-level' 'collect_dirs'
+  run "$TEST_GO_SCRIPT" 'top-level'
+  assert_success ''
+}
+
+@test "$SUITE: _GO_PLUGINS_DIR exists" {
+  mkdir -p "$TEST_GO_PLUGINS_DIR"
+  @go.create_test_command_script 'top-level' 'collect_dirs'
+  run "$TEST_GO_SCRIPT" 'top-level'
+  assert_success "$TEST_GO_PLUGINS_DIR"
+}
+
+@test "$SUITE: _GO_PLUGINS_DIR exists, search returns failure" {
+  mkdir -p "$TEST_GO_PLUGINS_DIR"
+  @go.create_test_command_script 'top' 'collect_dirs'
+  COLLECT_DIRS_SUCCESS_AFTER_NUM_ITERATIONS='0' run "$TEST_GO_SCRIPT" 'top'
+  assert_failure "$TEST_GO_PLUGINS_DIR"
+}
+
+@test "$SUITE: plugin without plugins dir finds _GO_PLUGINS_DIR" {
+  @go.create_test_command_script 'plugins/foo/bin/foo' 'collect_dirs'
+  COLLECT_DIRS_SUCCESS_AFTER_NUM_ITERATIONS='2' run "$TEST_GO_SCRIPT" 'foo'
+  assert_success "$TEST_GO_PLUGINS_DIR"
+}
+
+@test "$SUITE: plugin with plugins dir finds both plugins dirs" {
+  mkdir -p "$TEST_GO_PLUGINS_DIR/foo/bin/plugins"
+  @go.create_test_command_script 'plugins/foo/bin/foo' 'collect_dirs'
+  COLLECT_DIRS_SUCCESS_AFTER_NUM_ITERATIONS='2' run "$TEST_GO_SCRIPT" 'foo'
+  assert_success "$TEST_GO_PLUGINS_DIR/foo/bin/plugins" \
+    "$TEST_GO_PLUGINS_DIR"
+}
+
+@test "$SUITE: plugin with plugins dir, return success after first dir" {
+  mkdir -p "$TEST_GO_PLUGINS_DIR/foo/bin/plugins"
+  @go.create_test_command_script 'plugins/foo/bin/foo' 'collect_dirs'
+  COLLECT_DIRS_SUCCESS_AFTER_NUM_ITERATIONS='1' run "$TEST_GO_SCRIPT" 'foo'
+  assert_success "$TEST_GO_PLUGINS_DIR/foo/bin/plugins"
+}
+
+@test "$SUITE: plugin finds both plugins dirs, returns failure" {
+  mkdir -p "$TEST_GO_PLUGINS_DIR/foo/bin/plugins"
+  @go.create_test_command_script 'plugins/foo/bin/foo' 'collect_dirs'
+  COLLECT_DIRS_SUCCESS_AFTER_NUM_ITERATIONS='3' run "$TEST_GO_SCRIPT" 'foo'
+  assert_failure "$TEST_GO_PLUGINS_DIR/foo/bin/plugins" \
+    "$TEST_GO_PLUGINS_DIR"
+}
+
+@test "$SUITE: nested_plugin without plugins dir finds parent dirs" {
+  mkdir -p "$TEST_GO_PLUGINS_DIR/foo/bin/plugins/bar/bin"
+  @go.create_test_command_script 'plugins/foo/bin/foo' '@go bar'
+  @go.create_test_command_script 'plugins/foo/bin/plugins/bar/bin/bar' \
+    'collect_dirs'
+  COLLECT_DIRS_SUCCESS_AFTER_NUM_ITERATIONS='3' run "$TEST_GO_SCRIPT" 'foo'
+  assert_success "$TEST_GO_PLUGINS_DIR/foo/bin/plugins" \
+    "$TEST_GO_PLUGINS_DIR"
+}
+
+@test "$SUITE: nested_plugin with plugins dir finds all plugin dirs" {
+  mkdir -p "$TEST_GO_PLUGINS_DIR/foo/bin/plugins/bar/bin/plugins"
+  @go.create_test_command_script 'plugins/foo/bin/foo' '@go bar'
+  @go.create_test_command_script 'plugins/foo/bin/plugins/bar/bin/bar' \
+    'collect_dirs'
+  COLLECT_DIRS_SUCCESS_AFTER_NUM_ITERATIONS='3' run "$TEST_GO_SCRIPT" 'foo'
+  assert_success "$TEST_GO_PLUGINS_DIR/foo/bin/plugins/bar/bin/plugins" \
+    "$TEST_GO_PLUGINS_DIR/foo/bin/plugins" \
+    "$TEST_GO_PLUGINS_DIR"
+}
+
+@test "$SUITE: nested_plugin stops after parent plugin dir" {
+  @go.create_test_command_script 'plugins/foo/bin/foo' '@go bar'
+  @go.create_test_command_script 'plugins/foo/bin/plugins/bar/bin/bar' \
+    'collect_dirs'
+  COLLECT_DIRS_SUCCESS_AFTER_NUM_ITERATIONS='2' run "$TEST_GO_SCRIPT" 'foo'
+  # Note it doesn't have its own plugin dir this time.
+  assert_success "$TEST_GO_PLUGINS_DIR/foo/bin/plugins"
+}
+
+@test "$SUITE: nested_plugin with plugins dir finds all dirs, returns failure" {
+  mkdir -p "$TEST_GO_PLUGINS_DIR/foo/bin/plugins/bar/bin/plugins"
+  @go.create_test_command_script 'plugins/foo/bin/foo' '@go bar'
+  @go.create_test_command_script 'plugins/foo/bin/plugins/bar/bin/bar' \
+    'collect_dirs'
+  COLLECT_DIRS_SUCCESS_AFTER_NUM_ITERATIONS='4' run "$TEST_GO_SCRIPT" 'foo'
+  assert_failure "$TEST_GO_PLUGINS_DIR/foo/bin/plugins/bar/bin/plugins" \
+    "$TEST_GO_PLUGINS_DIR/foo/bin/plugins" \
+    "$TEST_GO_PLUGINS_DIR"
+}
+
+@test "$SUITE: /plugins/ in _GO_ROOTDIR, _GO_SCRIPTS_DIR (pathological)" {
+  local test_rootdir="$TEST_GO_ROOTDIR/plugins/plugins"
+  local test_go_script="$test_rootdir/go"
+  local test_scripts_dir="$test_rootdir/plugins"
+  local test_plugins_dir="$test_scripts_dir/plugins"
+  mkdir -p "$test_plugins_dir/foo/bin/plugins/bar/bin/plugins"
+
+  local line
+  while IFS= read -r line; do
+    line="${line%$'\r'}"
+    if [[ "$line" =~ go-core\.bash ]]; then
+      line=". '$_GO_CORE_DIR/go-core.bash' 'plugins'"
+    fi
+    printf '%s\n' "$line" >> "$test_go_script"
+  done < "$TEST_GO_SCRIPT"
+  chmod 700 "$test_go_script"
+
+  local foo_path="${test_plugins_dir#$BATS_TEST_ROOTDIR/}/foo/bin/foo"
+  local bar_path="${foo_path%/*}/plugins/bar/bin/bar"
+
+  # We can't use `@go.create_test_command_script` since we can't change the
+  # readonly `TEST_GO_*` variables.
+  create_bats_test_script "$foo_path" '@go bar'
+  create_bats_test_script "$bar_path" 'collect_dirs'
+
+  test_printf 'test_go_script: %s\n' "$test_go_script" >&2
+  test_printf 'test_plugins_dir: %s\n' "$test_plugins_dir" >&2
+  test_printf 'foo_path: %s\n' "${foo_path}" >&2
+  test_printf 'bar_path: %s\n' "${bar_path}" >&2
+  COLLECT_DIRS_SUCCESS_AFTER_NUM_ITERATIONS='10' run "$test_go_script" 'foo'
+  assert_failure "$test_plugins_dir/foo/bin/plugins/bar/bin/plugins" \
+    "$test_plugins_dir/foo/bin/plugins" \
+    "$test_plugins_dir"
+}