babel-parser: Add new internal ESLint rule to consistent error messages

.eslintrc.cjs

@@ -109,6 +109,7 @@ module.exports = {
             ),
           },
         ],
+        "@babel/development-internal/report-error-message-format": "error",
       },
     },
     {

eslint/babel-eslint-plugin-development-internal/README.md

@@ -68,3 +68,42 @@ and
   }
 }
 ```
+
+### `@babel/development-internal/report-error-message-format`
+
+This rule is inspired by https://github.com/not-an-aardvark/eslint-plugin-eslint-plugin/blob/master/docs/rules/report-message-format.md.
+
+Intended for use in `packages/babel-parser/src/**/*`. When enabled, this rule warns for inconsistently error messages format in arguments of `makeErrorTemplates` function calls.
+
+Basically, it starts with an uppercase Latin letter(A~Z) and ends with a period(.) or a question(?). But it can start with `'keyword'` or `` `code` `` to include JavaScript keywords or code in error messages.
+
+valid:
+
+```js
+makeErrorTemplates({ ThisIsAnError: "This is an error." });
+makeErrorTemplates({ ThisIsAnError: "'this' is an error." });
+makeErrorTemplates({ ThisIsAnError: "`this` is an error." });
+makeErrorTemplates({ ThisIsAnError: "This is an error?" });
+makeErrorTemplates({ ThisIsAnError: "'this' is an error?" });
+makeErrorTemplates({ ThisIsAnError: "`this` is an error?" });
+```
+
+invalid:
+
+```js
+makeErrorTemplates({ ThisIsAnError: 'this is an error.' });
+makeErrorTemplates({ ThisIsAnError: 'This is an error' });
+makeErrorTemplates({ ThisIsAnError: 'this is an error?' });
+makeErrorTemplates({ ThisIsAnError: '`this` is an error' });
+makeErrorTemplates({ ThisIsAnError: "'this' is an error" });
+```
+
+Example configuration:
+
+```js
+{
+  rules: {
+    "@babel/development-internal/report-error-message-format": "error"
+  }
+}
+```

eslint/babel-eslint-plugin-development-internal/src/index.js

@@ -1,7 +1,9 @@
 import dryErrorMessages from "./rules/dry-error-messages";
+import reportErrorMessageFormat from "./rules/report-error-message-format";
 
 export const rules = {
   "dry-error-messages": dryErrorMessages,
+  "report-error-message-format": reportErrorMessageFormat,
 };
 
 export default { rules };

eslint/babel-eslint-plugin-development-internal/src/rules/report-error-message-format.js

@@ -0,0 +1,31 @@
+const messageId = "mustMatchPattern";
+
+const pattern = /(('.*')|(`.*`)|[A-Z]).*(\.|\?)$/s;
+
+export default {
+  meta: {
+    type: "suggestion",
+    docs: {
+      description: "enforce @babel/parser's error message formatting.",
+    },
+    messages: {
+      [messageId]: `Report message does not match the pattern ${pattern.toString()}.`,
+    },
+  },
+  create({ report }) {
+    return {
+      "CallExpression[callee.type='Identifier'][callee.name='makeErrorTemplates'] > ObjectExpression > Property[value.type='Literal']"(
+        node,
+      ) {
+        const { value } = node;
+        if (typeof value.value === "string" && pattern.test(value.value)) {
+          return;
+        }
+        report({
+          node: value,
+          messageId,
+        });
+      },
+    };
+  },
+};

eslint/babel-eslint-plugin-development-internal/test/rules/report-error-message-formtat.js

@@ -0,0 +1,44 @@
+import RuleTester from "../../../babel-eslint-shared-fixtures/utils/RuleTester";
+import rule from "../../src/rules/report-error-message-format";
+
+const ruleTester = new RuleTester();
+
+ruleTester.run("report-error-message-format", rule, {
+  valid: [
+    "makeErrorTemplates({});",
+    'makeErrorTemplates({ ThisIsAnError: "This is an error." });',
+    `makeErrorTemplates({ ThisIsAnError: "'this' is an error." });`,
+    `makeErrorTemplates({ ThisIsAnError: "\`this\` is an error." });`,
+    `makeErrorTemplates({ ThisIsAnError: "This is an error?" });`,
+    `makeErrorTemplates({ ThisIsAnError: "'this' is an error?" });`,
+    `makeErrorTemplates({ ThisIsAnError: "\`this\` is an error?" });`,
+    'makeErrorTemplates({ ThisIsAnError: "This is\\nan error." });',
+    `makeErrorTemplates({ ThisIsAnError: "'this' is\\nan error." });`,
+    `makeErrorTemplates({ ThisIsAnError: "\`this\` is\\nan error." });`,
+    `makeErrorTemplates({ ThisIsAnError: "This is\\nan error?" });`,
+    `makeErrorTemplates({ ThisIsAnError: "'this' is\\nan error?" });`,
+    `makeErrorTemplates({ ThisIsAnError: "\`this\` is\\nan error?" });`,
+  ],
+  invalid: [
+    {
+      code: "makeErrorTemplates({ ThisIsAnError: 'this is an error.' });",
+      errors: [{ messageId: "mustMatchPattern" }],
+    },
+    {
+      code: "makeErrorTemplates({ ThisIsAnError: 'This is an error' });",
+      errors: [{ messageId: "mustMatchPattern" }],
+    },
+    {
+      code: "makeErrorTemplates({ ThisIsAnError: 'this is an error?' });",
+      errors: [{ messageId: "mustMatchPattern" }],
+    },
+    {
+      code: "makeErrorTemplates({ ThisIsAnError: '`this` is an error' });",
+      errors: [{ messageId: "mustMatchPattern" }],
+    },
+    {
+      code: `makeErrorTemplates({ ThisIsAnError: "'this' is an error" });`,
+      errors: [{ messageId: "mustMatchPattern" }],
+    },
+  ],
+});

packages/babel-cli/test/fixtures/babel/stdin --filename windows/stderr.txt

@@ -1 +1 @@
-SyntaxError: <CWD>\test.js: Missing semicolon (2:10)
+SyntaxError: <CWD>\test.js: Missing semicolon. (2:10)

packages/babel-cli/test/fixtures/babel/stdin --filename/stderr.txt

@@ -1 +1 @@
-SyntaxError: <CWD>/test.js: Missing semicolon (2:10)
+SyntaxError: <CWD>/test.js: Missing semicolon. (2:10)

packages/babel-core/test/fixtures/transformation/errors/syntax/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "Missing semicolon (2:10)"
+  "throws": "Missing semicolon. (2:10)"
 }