fix: clarify EPLUGINCONF error message

The message now specify if the step is required and if it allows to configure multiple plugins.

lib/definitions/errors.js

@@ -55,11 +55,13 @@ Your configuration for the \`tagFormat\` option is \`${stringify(tagFormat)}\`.`
 
 Your configuration for the \`tagFormat\` option is \`${stringify(tagFormat)}\`.`,
   }),
-  EPLUGINCONF: ({type, pluginConf}) => ({
+  EPLUGINCONF: ({type, multiple, required, pluginConf}) => ({
     message: `The \`${type}\` plugin configuration is invalid.`,
-    details: `The [${type} plugin configuration](${linkify(
-      `docs/usage/plugins.md#${toLower(type)}-plugin`
-    )}) if defined, must be a single or an array of plugins definition. A plugin definition is either a string or an object with a \`path\` property.
+    details: `The [${type} plugin configuration](${linkify(`docs/usage/plugins.md#${toLower(type)}-plugin`)}) ${
+      required ? 'is required and ' : ''
+    }must be ${
+      multiple ? 'a single or an array of plugins' : 'a single plugin'
+    } definition. A plugin definition is either a string or an object with a \`path\` property.
 
     Your configuration for the \`${type}\` plugin is \`${stringify(pluginConf)}\`.`,
   }),

lib/definitions/plugins.js

@@ -1,18 +1,18 @@
-const {isString, isFunction, isArray, isPlainObject} = require('lodash');
+const {isString, isPlainObject} = require('lodash');
 const {gitHead} = require('../git');
 const {RELEASE_TYPE, RELEASE_NOTES_SEPARATOR} = require('./constants');
 
-const validatePluginConfig = conf => isString(conf) || isString(conf.path) || isFunction(conf);
-
 module.exports = {
   verifyConditions: {
     default: ['@semantic-release/npm', '@semantic-release/github'],
-    configValidator: conf => !conf || (isArray(conf) ? conf : [conf]).every(conf => validatePluginConfig(conf)),
+    multiple: true,
+    required: false,
     pipelineConfig: () => ({settleAll: true}),
   },
   analyzeCommits: {
     default: '@semantic-release/commit-analyzer',
-    configValidator: conf => Boolean(conf) && validatePluginConfig(conf),
+    multiple: false,
+    required: true,
     outputValidator: output => !output || RELEASE_TYPE.includes(output),
     preprocess: ({commits, ...inputs}) => ({
       ...inputs,
@@ -22,12 +22,14 @@ module.exports = {
   },
   verifyRelease: {
     default: false,
-    configValidator: conf => !conf || (isArray(conf) ? conf : [conf]).every(conf => validatePluginConfig(conf)),
+    multiple: true,
+    required: false,
     pipelineConfig: () => ({settleAll: true}),
   },
   generateNotes: {
     default: ['@semantic-release/release-notes-generator'],
-    configValidator: conf => !conf || (isArray(conf) ? conf : [conf]).every(conf => validatePluginConfig(conf)),
+    multiple: true,
+    required: false,
     outputValidator: output => !output || isString(output),
     pipelineConfig: () => ({
       getNextInput: ({nextRelease, ...context}, notes) => ({
@@ -42,7 +44,8 @@ module.exports = {
   },
   prepare: {
     default: ['@semantic-release/npm'],
-    configValidator: conf => !conf || (isArray(conf) ? conf : [conf]).every(conf => validatePluginConfig(conf)),
+    multiple: true,
+    required: false,
     pipelineConfig: ({generateNotes}, logger) => ({
       getNextInput: async context => {
         const newGitHead = await gitHead({cwd: context.cwd});
@@ -60,7 +63,8 @@ module.exports = {
   },
   publish: {
     default: ['@semantic-release/npm', '@semantic-release/github'],
-    configValidator: conf => !conf || (isArray(conf) ? conf : [conf]).every(conf => validatePluginConfig(conf)),
+    multiple: true,
+    required: false,
     outputValidator: output => !output || isPlainObject(output),
     pipelineConfig: () => ({
       // Add `nextRelease` and plugin properties to published release
@@ -73,12 +77,14 @@ module.exports = {
   },
   success: {
     default: ['@semantic-release/github'],
-    configValidator: conf => !conf || (isArray(conf) ? conf : [conf]).every(conf => validatePluginConfig(conf)),
+    multiple: true,
+    required: false,
     pipelineConfig: () => ({settleAll: true}),
   },
   fail: {
     default: ['@semantic-release/github'],
-    configValidator: conf => !conf || (isArray(conf) ? conf : [conf]).every(conf => validatePluginConfig(conf)),
+    multiple: true,
+    required: false,
     pipelineConfig: () => ({settleAll: true}),
   },
 };

lib/plugins/index.js

@@ -2,6 +2,7 @@ const {identity, isPlainObject, omit, castArray, isUndefined} = require('lodash'
 const AggregateError = require('aggregate-error');
 const getError = require('../get-error');
 const PLUGINS_DEFINITIONS = require('../definitions/plugins');
+const {validateConfig} = require('./utils');
 const pipeline = require('./pipeline');
 const normalize = require('./normalize');
 
@@ -11,7 +12,7 @@ module.exports = (context, pluginsPath) => {
   const plugins = Object.entries(PLUGINS_DEFINITIONS).reduce(
     (
       plugins,
-      [type, {configValidator, default: def, pipelineConfig, postprocess = identity, preprocess = identity}]
+      [type, {multiple, required, default: def, pipelineConfig, postprocess = identity, preprocess = identity}]
     ) => {
       let pluginOpts;
 
@@ -23,8 +24,8 @@ module.exports = (context, pluginsPath) => {
         if (isPlainObject(options[type]) && !options[type].path && defaultPaths.length === 1) {
           [options[type].path] = defaultPaths;
         }
-        if (configValidator && !configValidator(options[type])) {
-          errors.push(getError('EPLUGINCONF', {type, pluginConf: options[type]}));
+        if (!validateConfig({multiple, required}, options[type])) {
+          errors.push(getError('EPLUGINCONF', {type, multiple, required, pluginConf: options[type]}));
           return plugins;
         }
         pluginOpts = options[type];

lib/plugins/utils.js

@@ -0,0 +1,18 @@
+const {isString, isFunction, castArray} = require('lodash');
+
+const validateSingleConfig = conf => {
+  conf = castArray(conf);
+  return conf.length === 1 && (isString(conf[0]) || isString(conf[0].path) || isFunction(conf[0]));
+};
+
+const validateMultipleConfig = conf => castArray(conf).every(conf => validateSingleConfig(conf));
+
+const validateConfig = ({multiple, required}, conf) => {
+  conf = castArray(conf).filter(Boolean);
+  if (required) {
+    return Boolean(conf) && conf.length >= 1 && (multiple ? validateMultipleConfig : validateSingleConfig)(conf);
+  }
+  return conf.length === 0 || (multiple ? validateMultipleConfig : validateSingleConfig)(conf);
+};
+
+module.exports = {validateConfig};