feat(event-names): add regex option

rlaffers · Apr 24, 2021 · 84b38c9 · 84b38c9
1 parent 4b1c715
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diff --git a/docs/rules/event-names.md b/docs/rules/event-names.md
@@ -1,6 +1,6 @@
 # Suggest consistent formatting of event names
 
-Suggest using event names formatted with the preconfigured style (MACRO_CASE, snake_case or camelCase).
+Suggest using event names formatted with the preconfigured style (MACRO_CASE, snake_case, camelCase or regex).
 
 # Rule Details
 
@@ -9,8 +9,9 @@ While the XState library neither enforces nor recommends any particular format f
 - MACRO_CASE (a.k.a. SCREAMING_SNAKE_CASE) [*default*]
 - snake_case
 - camelCase
+- regular expression
 
-The default MACRO_CASE for event names is an _unofficial_ convention, typically used within the XState community.
+The default MACRO*CASE for event names is an \_unofficial* convention, typically used within the XState community.
 
 Examples of **incorrect** code for this rule:
 
@@ -155,14 +156,19 @@ const obj = {
 
 ## Options
 
-| Option   | Required | Default     | Details                                                                               |
-| -------- | -------- | ----------- | ------------------------------------------------------------------------------------- |
-| [string] | No       | `macroCase` | Selects one of the available formatting styles: `macroCase`, `snakeCase`, `camelCase` |
+| Option   | Required | Default     | Details                                                                                        |
+| -------- | -------- | ----------- | ---------------------------------------------------------------------------------------------- |
+| [string] | No       | `macroCase` | Selects one of the available formatting styles: `macroCase`, `snakeCase`, `camelCase`, `regex` |
+| [object] | No       | `undefined` | The second option is an object with properties: `regex` (string)                               |
 
 ## Example
 
 ```json
 {
   "xstate/event-names": ["warn", "camelCase"]
 }
+
+{
+  "xstate/state-names": ["warn", "regex", { "regex": "^\\w+:\\w+$" }]
+}
 ```
diff --git a/lib/rules/event-names.js b/lib/rules/event-names.js
@@ -62,6 +62,12 @@ function containsWildcardOrDot(name) {
 const selectorSendEvent =
   'CallExpression[callee.name=/^createMachine$|^Machine$/] CallExpression[callee.name=/^send$|^sendParent$|^respond$|^raise$/]'
 
+/**
+ * Default regular expression for the regex option.
+ * @type {string}
+ */
+const defaultRegex = '^[a-z]*$'
+
 module.exports = {
   meta: {
     type: 'suggestion',
@@ -74,19 +80,38 @@ module.exports = {
     fixable: 'code',
     schema: [
       {
-        enum: ['macroCase', 'camelCase', 'snakeCase'],
+        enum: ['macroCase', 'camelCase', 'snakeCase', 'regex'],
+      },
+      {
+        type: 'object',
+        properties: {
+          regex: {
+            type: 'string',
+            format: 'regex',
+            default: defaultRegex,
+          },
+        },
+        additionalProperties: false,
       },
     ],
     messages: {
       invalidEventName:
         'Prefer "{{fixedEventName}}" over "{{eventName}}" event name',
       invalidSendEventName:
         'Wildcards in event names cannot be used when sending events.',
+      eventNameViolatesRegex:
+        'Event name "{{eventName}}" violates regular expression /{{regex}}/',
     },
   },
 
   create: function (context) {
     const mode = context.options[0] || 'macroCase'
+    const regexOption =
+      mode === 'regex'
+        ? (context.options[1] && context.options[1].regex) || defaultRegex
+        : null
+    const regex = regexOption !== null ? new RegExp(regexOption) : null
+
     return {
       'CallExpression[callee.name=/^createMachine$|^Machine$/] Property[key.name="on"] > ObjectExpression > Property': function (
         node
@@ -97,6 +122,16 @@ module.exports = {
         }
         const eventName =
           node.key.type === 'Identifier' ? node.key.name : node.key.value
+
+        if (regex && !regex.test(eventName)) {
+          context.report({
+            node,
+            data: { eventName, regex: regexOption },
+            messageId: 'eventNameViolatesRegex',
+          })
+          return
+        }
+
         const fixedEventName = fixEventName(eventName, mode)
         // quotes are needed only if the event name contains "." or "*"
         const quote = containsWildcardOrDot(eventName) ? "'" : ''
@@ -129,6 +164,16 @@ module.exports = {
             })
             return
           }
+
+          if (regex && !regex.test(eventName)) {
+            context.report({
+              node,
+              data: { eventName, regex: regexOption },
+              messageId: 'eventNameViolatesRegex',
+            })
+            return
+          }
+
           const fixedEventName = fixEventName(eventName, mode)
           if (eventName !== fixedEventName) {
             const quote = eventArg.raw[0]
@@ -158,6 +203,16 @@ module.exports = {
               })
               return
             }
+
+            if (regex && !regex.test(eventName)) {
+              context.report({
+                node,
+                data: { eventName, regex: regexOption },
+                messageId: 'eventNameViolatesRegex',
+              })
+              return
+            }
+
             const fixedEventName = fixEventName(eventName, mode)
             if (eventName !== fixedEventName) {
               const quote = type.value.raw[0]

diff --git a/tests/lib/rules/event-names.js b/tests/lib/rules/event-names.js
@@ -44,6 +44,15 @@ const tests = {
         }
       }
     `,
+    `
+      /* eslint event-names: [ "warn", "regex", { "regex": "^[a-z]+:[a-z0-9]+$" } ] */
+      createMachine({
+        on: {
+          'power:on': {},
+          'click:1': {},
+        },
+      })
+    `,
   ],
 
   invalid: [
@@ -315,6 +324,27 @@ const tests = {
         },
       ],
     },
+    {
+      code: `
+        /* eslint event-names: [ "warn", "regex", { "regex": "^[a-z]+:[a-z0-9]+$" } ] */
+        createMachine({
+          on: {
+            PowerOn: {},
+            power_on: {},
+          },
+        })
+      `,
+      errors: [
+        {
+          messageId: 'eventNameViolatesRegex',
+          data: { eventName: 'PowerOn', regex: '^[a-z]+:[a-z0-9]+$' },
+        },
+        {
+          messageId: 'eventNameViolatesRegex',
+          data: { eventName: 'power_on', regex: '^[a-z]+:[a-z0-9]+$' },
+        },
+      ],
+    },
   ],
 }