🎨 refactor how to collect 'require/import'

mysticatea · mysticatea · commit df979d317571 · 2019-09-05T10:08:58.000+09:00
diff --git a/lib/rules/file-extension-in-import.js b/lib/rules/file-extension-in-import.js
@@ -6,8 +6,8 @@
 
 const path = require("path")
 const fs = require("fs")
-const getImportExportTargets = require("../util/get-import-export-targets")
 const getTryExtensions = require("../util/get-try-extensions")
+const visitImport = require("../util/visit-import")
 const packageNamePattern = /^(?:@[^/\\]+[/\\])?[^/\\]+$/u
 const corePackageOverridePattern = /^(?:assert|async_hooks|buffer|child_process|cluster|console|constants|crypto|dgram|dns|domain|events|fs|http|http2|https|inspector|module|net|os|path|perf_hooks|process|punycode|querystring|readline|repl|stream|string_decoder|sys|timers|tls|trace_events|tty|url|util|v8|vm|worker_threads|zlib)[/\\]$/u
 
@@ -122,11 +122,8 @@ module.exports = {
             }
         }
 
-        return {
-            "Program:exit"(node) {
-                const opts = { optionIndex: 1 }
-                getImportExportTargets(context, node, opts).forEach(verify)
-            },
-        }
+        return visitImport(context, { optionIndex: 1 }, targets => {
+            targets.forEach(verify)
+        })
     },
 }
diff --git a/lib/rules/no-extraneous-import.js b/lib/rules/no-extraneous-import.js
@@ -7,9 +7,9 @@
 const checkExtraneous = require("../util/check-extraneous")
 const getAllowModules = require("../util/get-allow-modules")
 const getConvertPath = require("../util/get-convert-path")
-const getImportTargets = require("../util/get-import-export-targets")
 const getResolvePaths = require("../util/get-resolve-paths")
 const getTryExtensions = require("../util/get-try-extensions")
+const visitImport = require("../util/visit-import")
 
 module.exports = {
     meta: {
@@ -42,14 +42,8 @@ module.exports = {
             return {}
         }
 
-        return {
-            "Program:exit"(node) {
-                checkExtraneous(
-                    context,
-                    filePath,
-                    getImportTargets(context, node, false)
-                )
-            },
-        }
+        return visitImport(context, {}, targets => {
+            checkExtraneous(context, filePath, targets)
+        })
     },
 }
diff --git a/lib/rules/no-extraneous-require.js b/lib/rules/no-extraneous-require.js
@@ -7,9 +7,9 @@
 const checkExtraneous = require("../util/check-extraneous")
 const getAllowModules = require("../util/get-allow-modules")
 const getConvertPath = require("../util/get-convert-path")
-const getRequireTargets = require("../util/get-require-targets")
 const getResolvePaths = require("../util/get-resolve-paths")
 const getTryExtensions = require("../util/get-try-extensions")
+const visitRequire = require("../util/visit-require")
 
 module.exports = {
     meta: {
@@ -42,14 +42,8 @@ module.exports = {
             return {}
         }
 
-        return {
-            "Program:exit"() {
-                checkExtraneous(
-                    context,
-                    filePath,
-                    getRequireTargets(context, false)
-                )
-            },
-        }
+        return visitRequire(context, {}, targets => {
+            checkExtraneous(context, filePath, targets)
+        })
     },
 }
diff --git a/lib/rules/no-hide-core-modules.js b/lib/rules/no-hide-core-modules.js
@@ -11,8 +11,9 @@
 const path = require("path")
 const resolve = require("resolve")
 const getPackageJson = require("../util/get-package-json")
-const getRequireTargets = require("../util/get-require-targets")
-const getImportExportTargets = require("../util/get-import-export-targets")
+const mergeVisitorsInPlace = require("../util/merge-visitors-in-place")
+const visitImport = require("../util/visit-import")
+const visitRequire = require("../util/visit-require")
 
 const CORE_MODULES = new Set([
     "assert",
@@ -98,49 +99,57 @@ module.exports = {
         const ignoreIndirectDependencies = Boolean(
             options.ignoreIndirectDependencies
         )
+        const targets = []
 
-        return {
-            "Program:exit"(node) {
-                const targets = []
-                    .concat(
-                        getRequireTargets(context, true),
-                        getImportExportTargets(context, node, {
-                            includeCore: true,
-                        })
-                    )
-                    .filter(t => CORE_MODULES.has(t.moduleName))
+        return [
+            visitImport(context, { includeCore: true }, importTargets =>
+                targets.push(...importTargets)
+            ),
+            visitRequire(context, { includeCore: true }, requireTargets =>
+                targets.push(...requireTargets)
+            ),
+            {
+                "Program:exit"() {
+                    for (const target of targets.filter(t =>
+                        CORE_MODULES.has(t.moduleName)
+                    )) {
+                        const name = target.moduleName
+                        const allowed =
+                            allow.indexOf(name) !== -1 ||
+                            (ignoreDirectDependencies && deps.has(name)) ||
+                            (ignoreIndirectDependencies && !deps.has(name))
 
-                for (const target of targets) {
-                    const name = target.moduleName
-                    const allowed =
-                        allow.indexOf(name) !== -1 ||
-                        (ignoreDirectDependencies && deps.has(name)) ||
-                        (ignoreIndirectDependencies && !deps.has(name))
+                        if (allowed) {
+                            continue
+                        }
 
-                    if (allowed) {
-                        continue
-                    }
+                        const resolved = resolve.sync(name, {
+                            basedir: dirPath,
+                        })
+                        const isCore = resolved === name
 
-                    const resolved = resolve.sync(name, { basedir: dirPath })
-                    const isCore = resolved === name
+                        if (isCore) {
+                            continue
+                        }
 
-                    if (isCore) {
-                        continue
+                        context.report({
+                            node: target.node,
+                            loc: target.node.loc,
+                            message:
+                                "Unexpected import of third-party module '{{name}}'.",
+                            data: {
+                                name: path
+                                    .relative(dirPath, resolved)
+                                    .replace(BACK_SLASH, "/"),
+                            },
+                        })
                     }
-
-                    context.report({
-                        node: target.node,
-                        loc: target.node.loc,
-                        message:
-                            "Unexpected import of third-party module '{{name}}'.",
-                        data: {
-                            name: path
-                                .relative(dirPath, resolved)
-                                .replace(BACK_SLASH, "/"),
-                        },
-                    })
-                }
+                },
             },
-        }
+        ].reduce(
+            (mergedVisitor, thisVisitor) =>
+                mergeVisitorsInPlace(mergedVisitor, thisVisitor),
+            {}
+        )
     },
 }
diff --git a/lib/rules/no-missing-import.js b/lib/rules/no-missing-import.js
@@ -6,9 +6,9 @@
 
 const checkExistence = require("../util/check-existence")
 const getAllowModules = require("../util/get-allow-modules")
-const getImportExportTargets = require("../util/get-import-export-targets")
 const getResolvePaths = require("../util/get-resolve-paths")
 const getTryExtensions = require("../util/get-try-extensions")
+const visitImport = require("../util/visit-import")
 
 module.exports = {
     meta: {
@@ -40,10 +40,8 @@ module.exports = {
             return {}
         }
 
-        return {
-            "Program:exit"(node) {
-                checkExistence(context, getImportExportTargets(context, node))
-            },
-        }
+        return visitImport(context, {}, targets => {
+            checkExistence(context, targets)
+        })
     },
 }
diff --git a/lib/rules/no-missing-require.js b/lib/rules/no-missing-require.js
@@ -6,9 +6,9 @@
 
 const checkExistence = require("../util/check-existence")
 const getAllowModules = require("../util/get-allow-modules")
-const getRequireTargets = require("../util/get-require-targets")
 const getResolvePaths = require("../util/get-resolve-paths")
 const getTryExtensions = require("../util/get-try-extensions")
+const visitRequire = require("../util/visit-require")
 
 module.exports = {
     meta: {
@@ -40,10 +40,8 @@ module.exports = {
             return {}
         }
 
-        return {
-            "Program:exit"() {
-                checkExistence(context, getRequireTargets(context))
-            },
-        }
+        return visitRequire(context, {}, targets => {
+            checkExistence(context, targets)
+        })
     },
 }
diff --git a/lib/rules/no-unpublished-import.js b/lib/rules/no-unpublished-import.js
@@ -7,9 +7,9 @@
 const checkPublish = require("../util/check-publish")
 const getAllowModules = require("../util/get-allow-modules")
 const getConvertPath = require("../util/get-convert-path")
-const getImportExportTargets = require("../util/get-import-export-targets")
 const getResolvePaths = require("../util/get-resolve-paths")
 const getTryExtensions = require("../util/get-try-extensions")
+const visitImport = require("../util/visit-import")
 
 module.exports = {
     meta: {
@@ -42,14 +42,8 @@ module.exports = {
             return {}
         }
 
-        return {
-            "Program:exit"(node) {
-                checkPublish(
-                    context,
-                    filePath,
-                    getImportExportTargets(context, node)
-                )
-            },
-        }
+        return visitImport(context, {}, targets => {
+            checkPublish(context, filePath, targets)
+        })
     },
 }
diff --git a/lib/rules/no-unpublished-require.js b/lib/rules/no-unpublished-require.js
@@ -7,9 +7,9 @@
 const checkPublish = require("../util/check-publish")
 const getAllowModules = require("../util/get-allow-modules")
 const getConvertPath = require("../util/get-convert-path")
-const getRequireTargets = require("../util/get-require-targets")
 const getResolvePaths = require("../util/get-resolve-paths")
 const getTryExtensions = require("../util/get-try-extensions")
+const visitRequire = require("../util/visit-require")
 
 module.exports = {
     meta: {
@@ -42,10 +42,8 @@ module.exports = {
             return {}
         }
 
-        return {
-            "Program:exit"() {
-                checkPublish(context, filePath, getRequireTargets(context))
-            },
-        }
+        return visitRequire(context, {}, targets => {
+            checkPublish(context, filePath, targets)
+        })
     },
 }
diff --git a/lib/rules/no-unsupported-features/es-syntax.js b/lib/rules/no-unsupported-features/es-syntax.js
@@ -9,6 +9,7 @@ const { getInnermostScope } = require("eslint-utils")
 const { Range } = require("semver") //eslint-disable-line no-unused-vars
 const getConfiguredNodeVersion = require("../../util/get-configured-node-version")
 const getSemverRange = require("../../util/get-semver-range")
+const mergeVisitorsInPlace = require("../../util/merge-visitors-in-place")
 
 const getOrSet = /^(?:g|s)et$/u
 const features = {
@@ -405,41 +406,6 @@ function normalizeScope(initialScope, node) {
     return scope
 }
 
-/**
- * Merge two visitors.
- * @param {Visitor} x The visitor which is assigned.
- * @param {Visitor} y The visitor which is assigning.
- * @returns {Visitor} `x`.
- */
-function merge(x, y) {
-    for (const key of Object.keys(y)) {
-        if (typeof x[key] === "function") {
-            if (x[key]._handlers == null) {
-                const fs = [x[key], y[key]]
-                x[key] = dispatch.bind(null, fs)
-                x[key]._handlers = fs
-            } else {
-                x[key]._handlers.push(y[key])
-            }
-        } else {
-            x[key] = y[key]
-        }
-    }
-    return x
-}
-
-/**
- * Dispatch all given functions with a node.
- * @param {function[]} handlers The function list to call.
- * @param {Node} node The AST node to be handled.
- * @returns {void}
- */
-function dispatch(handlers, node) {
-    for (const h of handlers) {
-        h(node)
-    }
-}
-
 /**
  * Define the visitor object as merging the rules of eslint-plugin-es.
  * @param {RuleContext} context The rule context.
@@ -514,7 +480,7 @@ function defineVisitor(context, options) {
                         }
                     },
                 }
-                return merge(visitor, rule.create(thisContext))
+                return mergeVisitorsInPlace(visitor, rule.create(thisContext))
             }, {})
     )
 }
diff --git a/lib/util/get-require-targets.js b/lib/util/get-require-targets.js
diff --git a/lib/util/merge-visitors-in-place.js b/lib/util/merge-visitors-in-place.js
diff --git a/lib/util/visit-import.js b/lib/util/visit-import.js
diff --git a/lib/util/visit-require.js b/lib/util/visit-require.js
