test: add basic tests for dependency-graph & linters

Author: keithamus

lib/rules/unused-export.js

@@ -1,4 +1,4 @@
-const {entries, imported} = require('../dependency-graph')
+const depGraph = require('../dependency-graph')
 
 module.exports = {
   meta: {
@@ -7,9 +7,9 @@ module.exports = {
 
   create(context) {
     const filename = context.getFilename()
-    const {identifiers} = imported()
+    const {identifiers} = depGraph.imported()
 
-    if (entries.has(filename)) {
+    if (depGraph.entries.has(filename)) {
       return {}
     }
 

lib/rules/unused-module.js

@@ -1,4 +1,4 @@
-const {entries, imported} = require('../dependency-graph')
+const depGraph = require('../dependency-graph')
 
 module.exports = {
   meta: {
@@ -8,13 +8,13 @@ module.exports = {
   create(context) {
     const filename = context.getFilename()
 
-    if (entries.has(filename)) {
+    if (depGraph.entries.has(filename)) {
       return {}
     }
 
     return {
       Program(node) {
-        const {filenames} = imported()
+        const {filenames} = depGraph.imported()
         if (!filenames.has(filename)) {
           context.report(node, 'Module was not imported by any files.')
         }

package-lock.json

@@ -66,6 +66,7 @@
     "eslint": ">=6.5.1",
     "flow-bin": ">=0.110.1",
     "graphql": ">=14.5.8",
-    "mocha": ">=6.2.2"
+    "mocha": ">=6.2.2",
+    "rimraf": "^3.0.0"
   }
 }

package.json

@@ -0,0 +1,55 @@
+const dependencyGraph = require('../lib/dependency-graph')
+const assert = require('assert')
+const {describe, it, before, after} = require('mocha')
+const rimraf = require('rimraf')
+const {resolve} = require('path')
+const {mkdirSync, writeFileSync, readFileSync, symlinkSync} = require('fs')
+describe('dependency-graph', () => {
+  it('has entries set', () => {
+    assert(dependencyGraph.entries instanceof Set)
+  })
+  it('has dependencyGraph map', () => {
+    assert(dependencyGraph.dependencyGraph instanceof Map)
+  })
+  it('has imported function', () => {
+    assert.equal(typeof dependencyGraph.imported, 'function')
+  })
+  describe('imported', () => {
+    before(() => {
+      rimraf.sync('./fixtures')
+      mkdirSync('./fixtures')
+      writeFileSync('./fixtures/index.js', ``)
+      writeFileSync('./fixtures/one.js', ``)
+      symlinkSync('./fixtures/one.js', './fixtures/link.js')
+      const graph = {imports: new Map(), exports: new Set()}
+      graph.imports.set(resolve('./fixtures/one.js'), new Set(['a', 'b']))
+      dependencyGraph.dependencyGraph.set('./fixtures/index.js', graph)
+    })
+    after(() => {
+      rimraf.sync('./fixtures')
+      dependencyGraph.dependencyGraph.clear()
+    })
+    it('gathers all imported files from dependencyGraph', () => {
+      const {filenames} = dependencyGraph.imported()
+      assert.deepEqual([...filenames], [
+        resolve('./fixtures/one.js')
+      ])
+    })
+    it('gathers all imported identifiers from dependencyGraph', () => {
+      const {identifiers} = dependencyGraph.imported()
+      assert.deepEqual([...identifiers], [
+        resolve('./fixtures/one.js#a'),
+        resolve('./fixtures/one.js#b')
+      ])
+    })
+    it('follows symlinks', () => {
+      const graph = dependencyGraph.dependencyGraph.get('./fixtures/index.js')
+      graph.imports.delete('./fixtures/one.js')
+      graph.imports.set('./fixtures/link.js', new Set(['a', 'b']))
+      const {filenames} = dependencyGraph.imported()
+      assert.deepEqual([...filenames], [
+        resolve('./fixtures/one.js'),
+      ])
+    })
+  })
+})

tests/dependency-graph.js

@@ -0,0 +1,95 @@
+const {describe, beforeEach, afterEach} = require('mocha')
+const depGraph = require('../lib/dependency-graph')
+var rule = require('../lib/rules/unused-export')
+var RuleTester = require('eslint').RuleTester
+var ruleTester = new RuleTester()
+
+describe('dependency-graph', () => {
+  const originalDepGraphImport = depGraph.imported
+  beforeEach(() => {
+    depGraph.imported = () => ({
+      identifiers: new Set(['a.js#*', 'b.js#foo', 'c.js#default'])
+    })
+  })
+
+  afterEach(() => {
+    depGraph.imported = originalDepGraphImport
+  })
+
+  ruleTester.run('unused-export', rule, {
+    valid: [
+      {
+        code: 'export const foo = 1',
+        parserOptions: {ecmaVersion: 2015, sourceType: 'module'},
+        filename: 'a.js'
+      },
+      {
+        code: 'export const foo = 1',
+        parserOptions: {ecmaVersion: 2015, sourceType: 'module'},
+        filename: 'b.js'
+      },
+      {
+        code: 'export default 1',
+        parserOptions: {ecmaVersion: 2015, sourceType: 'module'},
+        filename: 'c.js'
+      }
+    ],
+    invalid: [
+      {
+        code: 'export default 1',
+        parserOptions: {ecmaVersion: 2015, sourceType: 'module'},
+        filename: 'b.js',
+        errors: [
+          {
+            message: 'Export was not imported by any modules.',
+            type: 'ExportDefaultDeclaration'
+          }
+        ]
+      },
+      {
+        code: 'export const bar = 1',
+        parserOptions: {ecmaVersion: 2015, sourceType: 'module'},
+        filename: 'b.js',
+        errors: [
+          {
+            message: 'Export was not imported by any modules.',
+            type: 'ExportNamedDeclaration'
+          }
+        ]
+      },
+      {
+        code: 'export const foo = 1',
+        parserOptions: {ecmaVersion: 2015, sourceType: 'module'},
+        filename: 'c.js',
+        errors: [
+          {
+            message: 'Export was not imported by any modules.',
+            type: 'ExportNamedDeclaration'
+          }
+        ]
+      },
+      {
+        code: 'export default 1',
+        parserOptions: {ecmaVersion: 2015, sourceType: 'module'},
+        filename: 'd.js',
+        errors: [
+          {
+            message: 'Export was not imported by any modules.',
+            type: 'ExportDefaultDeclaration'
+          }
+        ]
+      },
+      {
+        code: 'export const foo = 1',
+        parserOptions: {ecmaVersion: 2015, sourceType: 'module'},
+        filename: 'd.js',
+        errors: [
+          {
+            message: 'Export was not imported by any modules.',
+            type: 'ExportNamedDeclaration'
+          }
+        ]
+      }
+    ]
+  })
+})

tests/unused-export.js

@@ -0,0 +1,45 @@
+const {describe, beforeEach, afterEach} = require('mocha')
+const depGraph = require('../lib/dependency-graph')
+var rule = require('../lib/rules/unused-module')
+var RuleTester = require('eslint').RuleTester
+var ruleTester = new RuleTester()
+
+describe('dependency-graph', () => {
+  const originalDepGraphImport = depGraph.imported
+  beforeEach(() => {
+    depGraph.entries.add('a.js')
+    depGraph.imported = () => ({
+      filenames: new Set(['b.js'])
+    })
+  })
+
+  afterEach(() => {
+    depGraph.entries.clear()
+    depGraph.imported = originalDepGraphImport
+  })
+
+  ruleTester.run('unused-modules', rule, {
+    valid: [
+      {
+        code: 'foo',
+        filename: 'a.js'
+      },
+      {
+        code: 'foo',
+        filename: 'b.js'
+      }
+    ],
+    invalid: [
+      {
+        code: 'foo',
+        filename: 'c.js',
+        errors: [
+          {
+            message: 'Module was not imported by any files.',
+            type: 'Program'
+          }
+        ]
+      }
+    ]
+  })
+})