Merge branch 'add-message-resolver-config-hook' into 'master'

Add message resolver config hook

See merge request kdanmobile/shared-code-base/gems/error_response!47

Author: 蔡耀賢

CHANGELOG.md

@@ -1,3 +1,8 @@
+## [1.3.0] - 2026-06-02
+- Add `config.error_message_resolver` extension hook to customize `ErrorResponse::Helper#error_response` without monkey patching.
+- Add compatibility support for both keyword and positional resolver signatures.
+- Add RSpec coverage for resolver behavior and fallback handling.
+
 ## [1.2.1] - 2026-04-08
 - Patch addressable to 2.9.0.
   - Fix Regular Expression Denial of Service in Addressable templates.

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    error_response (1.2.1)
+    error_response (1.3.0)
       activesupport (~> 7.2.3.1)
 
 GEM

README.md

@@ -44,6 +44,103 @@ ErrorResponse.configure do |config|
 end
 ```
 
+### Error Message Resolver
+
+You can provide an extension hook to customize the message passed into `ErrorResponse::Helper#error_response` without monkey patching.
+
+When `error_response` is called, the gem invokes `ErrorResponse.resolve_error_message` before building the API payload. The resolved value is then passed to `ErrorResponse.to_api` as the optional message suffix.
+
+```ruby
+ErrorResponse.configure do |config|
+  config.error_message_resolver = lambda do |key:, error_message:, error_data:, context:|
+    # Return a string message, nil, or any value accepted by `to_api`.
+    # context is the current controller instance when called from helper.
+    "customized message for #{key}"
+  end
+end
+```
+
+#### Resolver arguments
+
+| Argument | Description |
+| --- | --- |
+| `key` | The error key passed to `error_response` (e.g. `:bad_request_1`). |
+| `error_message` | The optional custom message passed to `error_response`. |
+| `error_data` | The optional hash or array passed to `error_response`. |
+| `context` | The current controller instance when called from `ErrorResponse::Helper`. `nil` when calling `ErrorResponse.resolve_error_message` directly. |
+
+#### Return value
+
+- Return a `String` to append after the YAML-defined message (e.g. `"bad request 1: customized message for bad_request_1"`).
+- Return `nil` to keep only the YAML-defined message (no suffix is appended).
+- If the resolver is not configured, does not respond to `call`, or raises an exception, the original `error_message` is used as a safe fallback.
+
+#### Supported resolver signatures
+
+Keyword arguments (recommended):
+
+```ruby
+config.error_message_resolver = lambda do |key:, error_message:, error_data:, context:|
+  error_message
+end
+```
+
+Positional arguments (backward compatible):
+
+```ruby
+config.error_message_resolver = lambda do |key, error_message, error_data, context|
+  error_message
+end
+```
+
+`**kwargs` style:
+
+```ruby
+config.error_message_resolver = lambda do |**kwargs|
+  kwargs[:error_message]
+end
+```
+
+Method object:
+
+```ruby
+class ErrorMessageResolver
+  def call(key:, error_message:, error_data:, context:)
+    error_message
+  end
+end
+
+ErrorResponse.configure do |config|
+  config.error_message_resolver = ErrorMessageResolver.new
+end
+```
+
+#### Example with `error_response`
+
+Given this resolver:
+
+```ruby
+ErrorResponse.configure do |config|
+  config.error_message_resolver = lambda do |key:, error_message:, error_data:, context:|
+    data = error_data.is_a?(Hash) ? error_data : {}
+    I18n.t("errors.#{key}", default: error_message, **data)
+  end
+end
+```
+
+Calling `error_response(:bad_request_1, 'no required data', { a: 1 })` produces:
+
+```json
+{
+  "error_code": 400001,
+  "error_message": "bad request 1: no required data",
+  "error_key": "bad_request_1",
+  "a": 1
+}
+```
+
+The resolver can rewrite `error_message` before it is appended. `error_data` is merged into the JSON response after message resolution and is not modified by the resolver.
+
 
 ## Usage
 
@@ -68,7 +165,7 @@ return success_response(data) if success?
 ```
 
 > response status: 200
-> 
+>
 > response body:
 
 ```json
@@ -90,7 +187,7 @@ return error_response(:bad_request_1) if failed?
 ```
 
 > response status: 400
-> 
+>
 > response body:
 
 ```json
@@ -103,13 +200,15 @@ return error_response(:bad_request_1) if failed?
 
 You can also provide your custom error message and error data. If error data is a hash, it will be merged into the json response; If it is an array, it will be merged into the json response with an `error_data` key.
 
+When `config.error_message_resolver` is configured, the custom message is passed through the resolver before being appended to the YAML-defined message. See [Error Message Resolver](#error-message-resolver) for details.
+
 ```ruby
 # in controller actions
 return error_response(:bad_request_1, 'no required data', { a: 1, b: 2 }) if failed?
 ```
 
 > response status: 400
-> 
+>
 > response body:
 
 ```json
@@ -148,10 +247,6 @@ ErrorResponse.to_hash(:bad_request_1)
 
 gives you
 
-> response status: 400
-> 
-> response body: 
-
 ```json
 {
   "error_code": 400001,
@@ -160,6 +255,23 @@ gives you
 }
 ```
 
+Resolve error message with optional resolver hook
+
+```ruby
+ErrorResponse.resolve_error_message(
+  key: :bad_request_1,
+  error_message: "no required data",
+  error_data: { field: "email" },
+  context: controller # optional
+)
+```
+
+gives you the resolved message string (or the original `error_message` when no resolver is configured), for example:
+
+```
+"no required data"
+```
+
 ## Security
 
 If you would like to report a security issue, please review the [Security Policy](SECURITY.md).

VERSION.md

@@ -1 +1 @@
-1.2.1
+1.3.0

lib/error_response.rb

@@ -9,6 +9,8 @@
 require "error_response/request_error"
 
 module ErrorResponse
+  RESOLVER_KEYWORD_PARAMETER_TYPES = %i[key keyreq keyrest].freeze
+
   class << self
     attr_writer :configuration
 
@@ -41,8 +43,25 @@ def to_api(key, message = nil)
       }
     end
 
+    def resolve_error_message(key:, error_message: nil, error_data: {}, context: nil)
+      resolver = configuration.error_message_resolver
+      return error_message unless resolver.respond_to?(:call)
+
+      call_resolver(resolver, key, error_message, error_data, context)
+    rescue StandardError
+      error_message
+    end
+
     private
 
+    def call_resolver(resolver, key, error_message, error_data, context)
+      if resolver_parameters(resolver).any? { |parameter| RESOLVER_KEYWORD_PARAMETER_TYPES.include?(parameter[0]) }
+        resolver.call(key: key, error_message: error_message, error_data: error_data, context: context)
+      else
+        resolver.call(key, error_message, error_data, context)
+      end
+    end
+
     def yaml_hash
       return @hash unless @hash.nil?
 
@@ -101,5 +120,11 @@ def permitted_classes
         NilClass
       ]
     end
+
+    def resolver_parameters(resolver)
+      resolver.parameters
+    rescue StandardError
+      resolver.method(:call).parameters
+    end
   end
 end

lib/error_response/configuration.rb

@@ -2,10 +2,11 @@
 
 module ErrorResponse
   class Configuration
-    attr_accessor :yaml_config_path
+    attr_accessor :yaml_config_path, :error_message_resolver
 
     def initialize
       @yaml_config_path = ENV["YAML_CONFIG_PATH"] || "config/error_response.yml"
+      @error_message_resolver = nil
     end
   end
 end

lib/error_response/helper.rb

@@ -17,7 +17,13 @@ def success_response(data = {})
     end
 
     def error_response(key, error_message = nil, error_data = {})
-      render_content = ErrorResponse.to_api(key, error_message).deep_dup
+      resolved_message = ErrorResponse.resolve_error_message(
+        key: key,
+        error_message: error_message,
+        error_data: error_data,
+        context: self
+      )
+      render_content = ErrorResponse.to_api(key, resolved_message).deep_dup
       if error_data.is_a?(Hash) && !error_data.empty?
         render_content[:json] = render_content[:json].merge(error_data)
       elsif error_data.is_a?(Array) && !error_data.empty?