Add defineDocumentVisitor to parserServices (#119)

* Add defineDocumentVisitor to parserServices

* fix

* fix

* Changed getTemplateBodyTokenStore to work even if `<template>` is missing

* Add testcase

* fix

Author: ota-meshi

README.md

@@ -203,6 +203,7 @@ See also to [here](https://github.com/vuejs/rfcs/blob/master/active-rfcs/0043-sf
     - `getTemplateBodyTokenStore()` ... returns ESLint `TokenStore` to get the tokens of `<template>`.
     - `getDocumentFragment()` ... returns the root `VDocumentFragment`.
     - `defineCustomBlocksVisitor(context, customParser, rule, scriptVisitor)` ... returns ESLint visitor that parses and traverses the contents of the custom block.
+    - `defineDocumentVisitor(documentVisitor, options)` ... returns ESLint visitor to traverses the document.
 - [ast.md](./docs/ast.md) is `<template>` AST specification.
 - [mustache-interpolation-spacing.js](https://github.com/vuejs/eslint-plugin-vue/blob/b434ff99d37f35570fa351681e43ba2cf5746db3/lib/rules/mustache-interpolation-spacing.js) is an example.
 

src/parser-services.ts

@@ -56,6 +56,16 @@ export interface ParserServices {
         options?: { templateBodyTriggerSelector: "Program" | "Program:exit" },
     ): object
 
+    /**
+     * Define handlers to traverse the document.
+     * @param documentVisitor The document handlers.
+     * @param options The options. This is optional.
+     */
+    defineDocumentVisitor(
+        documentVisitor: { [key: string]: (...args: any) => void },
+        options?: { triggerSelector: "Program" | "Program:exit" },
+    ): object
+
     /**
      * Define handlers to traverse custom blocks.
      * @param context The rule context.
@@ -103,6 +113,8 @@ export function define(
     const templateBodyEmitters = new Map<string, EventEmitter>()
     const stores = new WeakMap<object, TokenStore>()
 
+    const documentEmitters = new Map<string, EventEmitter>()
+
     const customBlocksEmitters = new Map<
         | ESLintCustomBlockParser["parseForESLint"]
         | ESLintCustomBlockParser["parse"],
@@ -180,6 +192,63 @@ export function define(
             return scriptVisitor
         },
 
+        /**
+         * Define handlers to traverse the document.
+         * @param documentVisitor The document handlers.
+         * @param options The options. This is optional.
+         */
+        defineDocumentVisitor(
+            documentVisitor: { [key: string]: (...args: any) => void },
+            options?: { triggerSelector: "Program" | "Program:exit" },
+        ): object {
+            const scriptVisitor: { [key: string]: (...args: any) => void } = {}
+            if (!document) {
+                return scriptVisitor
+            }
+
+            const documentTriggerSelector =
+                options?.triggerSelector ?? "Program:exit"
+
+            let emitter = documentEmitters.get(documentTriggerSelector)
+
+            // If this is the first time, initialize the intermediate event emitter.
+            if (emitter == null) {
+                emitter = new EventEmitter()
+                emitter.setMaxListeners(0)
+                documentEmitters.set(documentTriggerSelector, emitter)
+
+                const programExitHandler =
+                    scriptVisitor[documentTriggerSelector]
+                scriptVisitor[documentTriggerSelector] = (node) => {
+                    try {
+                        if (typeof programExitHandler === "function") {
+                            programExitHandler(node)
+                        }
+
+                        // Traverse document.
+                        const generator = new NodeEventGenerator(emitter!, {
+                            visitorKeys: KEYS,
+                            fallback: getFallbackKeys,
+                        })
+                        traverseNodes(document, generator)
+                    } finally {
+                        // eslint-disable-next-line @mysticatea/ts/ban-ts-ignore
+                        // @ts-ignore
+                        scriptVisitor[documentTriggerSelector] =
+                            programExitHandler
+                        documentEmitters.delete(documentTriggerSelector)
+                    }
+                }
+            }
+
+            // Register handlers into the intermediate event emitter.
+            for (const selector of Object.keys(documentVisitor)) {
+                emitter.on(selector, documentVisitor[selector])
+            }
+
+            return scriptVisitor
+        },
+
         /**
          * Define handlers to traverse custom blocks.
          * @param context The rule context.
@@ -331,14 +400,13 @@ export function define(
          * @returns The token store of template body.
          */
         getTemplateBodyTokenStore(): TokenStore {
-            const ast = rootAST.templateBody
-            const key = ast || stores
+            const key = document || stores
             let store = stores.get(key)
 
             if (!store) {
                 store =
-                    ast != null
-                        ? new TokenStore(ast.tokens, ast.comments)
+                    document != null
+                        ? new TokenStore(document.tokens, document.comments)
                         : new TokenStore([], [])
                 stores.set(key, store)
             }

test/define-document-visitor.js

@@ -0,0 +1,92 @@
+/**
+ * @author Yosuke Ota <https://github.com/ota-meshi>
+ */
+"use strict"
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const assert = require("assert")
+const path = require("path")
+const eslint = require("eslint")
+const Linter = eslint.Linter
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+const PARSER_PATH = path.resolve(__dirname, "../src/index.ts")
+
+//------------------------------------------------------------------------------
+// Tests
+//------------------------------------------------------------------------------
+
+describe("parserServices.defineDocumentVisitor tests", () => {
+    it("should be able to visit the document using defineDocumentVisitor.", () => {
+        const code = `
+<template>
+{{forbidden}}
+{{foo()}}
+{{ok}}
+</template>
+<style>
+.ng {
+    font: v-bind(forbidden)
+}
+.call {
+    font: v-bind('foo()')
+}
+.ok {
+    font: v-bind(ok)
+}
+</style>`
+
+        const linter = new Linter()
+
+        linter.defineParser(PARSER_PATH, require(PARSER_PATH))
+        linter.defineRule("test-no-forbidden", {
+            create(context) {
+                return context.parserServices.defineDocumentVisitor({
+                    'Identifier[name="forbidden"]'(node) {
+                        context.report({
+                            node,
+                            message: 'no "forbidden"',
+                        })
+                    },
+                })
+            },
+        })
+        linter.defineRule("test-no-call", {
+            create(context) {
+                return context.parserServices.defineDocumentVisitor({
+                    CallExpression(node) {
+                        context.report({
+                            node,
+                            message: "no call",
+                        })
+                    },
+                })
+            },
+        })
+        const messages = linter.verify(code, {
+            parser: PARSER_PATH,
+            parserOptions: {
+                ecmaVersion: 2018,
+            },
+            rules: {
+                "test-no-forbidden": "error",
+                "test-no-call": "error",
+            },
+        })
+        assert.strictEqual(messages.length, 4)
+        assert.strictEqual(messages[0].message, 'no "forbidden"')
+        assert.strictEqual(messages[0].line, 3)
+        assert.strictEqual(messages[1].message, "no call")
+        assert.strictEqual(messages[1].line, 4)
+        assert.strictEqual(messages[2].message, 'no "forbidden"')
+        assert.strictEqual(messages[2].line, 9)
+        assert.strictEqual(messages[3].message, "no call")
+        assert.strictEqual(messages[3].line, 12)
+    })
+})