feat: improve forSubpaths option (add fromInside and fromOuside sub-options)

Author: chapa

src/rules/prefer-alias.js

@@ -49,6 +49,22 @@ const getSiblingsMaxNestingLevel = options => {
   return -1
 }
 
+const optionForSubpathsMatches = (options, currentFileIsInsideAlias) => {
+  if (options.forSubpaths === true) {
+    return true
+  }
+  if (options.forSubpaths) {
+    if (currentFileIsInsideAlias && options.forSubpaths.fromInside) {
+      return true
+    }
+    if (!currentFileIsInsideAlias && options.forSubpaths.fromOutside) {
+      return true
+    }
+  }
+
+  return false
+}
+
 export default {
   create: context => {
     const currentFile = context.getFilename()
@@ -107,12 +123,17 @@ export default {
           matchingAlias &&
           P.relative(matchingAlias.path, currentFile).split(P.sep).length - 1
 
+        const currentFileIsInsideAlias =
+          matchingAlias &&
+          !(P.relative(matchingAlias.path, currentFile) |> startsWith('..'))
+
         const shouldAlias =
           !hasAlias &&
           ((importWithoutAlias |> isParentImport) ||
             ((importWithoutAlias |> isSiblingImport) &&
               currentFileNestingLevel <= siblingsMaxNestingLevel) ||
-            ((importWithoutAlias |> isSubpathImport) && options.forSubpaths))
+            ((importWithoutAlias |> isSubpathImport) &&
+              optionForSubpathsMatches(options, currentFileIsInsideAlias)))
         if (shouldAlias) {
           if (!matchingAlias) {
             return undefined
@@ -145,7 +166,8 @@ export default {
           !isDirectAlias &&
           (((importWithoutAlias |> isSiblingImport) &&
             currentFileNestingLevel > siblingsMaxNestingLevel) ||
-            ((importWithoutAlias |> isSubpathImport) && !options.forSubpaths))
+            ((importWithoutAlias |> isSubpathImport) &&
+              !optionForSubpathsMatches(options, currentFileIsInsideAlias)))
         if (shouldUnalias) {
           return context.report({
             fix: fixer =>
@@ -190,8 +212,26 @@ export default {
             ],
           },
           forSubpaths: {
-            default: false,
-            type: 'boolean',
+            anyOf: [
+              {
+                default: false,
+                type: 'boolean',
+              },
+              {
+                additionalProperties: false,
+                properties: {
+                  fromInside: {
+                    default: false,
+                    type: 'boolean',
+                  },
+                  fromOutside: {
+                    default: false,
+                    type: 'boolean',
+                  },
+                },
+                type: 'object',
+              },
+            ],
           },
         },
         type: 'object',

src/rules/prefer-alias.spec.js

@@ -239,31 +239,125 @@ export default tester(
           plugins: [
             [
               packageName`babel-plugin-module-resolver`,
-              { alias: { '@': '.' } },
+              { alias: { '@components': './components' } },
             ],
           ],
         }),
-        'sub/foo.js': '',
+      })
+
+      const eslintConfig = {
+        rules: {
+          'self/self': [
+            'error',
+            {
+              forSubpaths: true,
+            },
+          ],
+        },
+      }
+      expect(
+        lint("import foo from './components/foo'", {
+          eslintConfig,
+        }),
+      ).toEqual({
+        messages: [
+          "Unexpected subpath import './components/foo'. Use '@components/foo' instead",
+        ],
+        output: "import foo from '@components/foo'",
       })
       expect(
         lint("import foo from './sub/foo'", {
-          eslintConfig: {
-            rules: {
-              'self/self': [
-                'error',
-                {
-                  forSubpaths: true,
-                },
-              ],
+          eslintConfig,
+          filename: './components/bar.js',
+        }),
+      ).toEqual({
+        messages: [
+          "Unexpected subpath import './sub/foo'. Use '@components/sub/foo' instead",
+        ],
+        output: "import foo from '@components/sub/foo'",
+      })
+    },
+    'alias for subpaths from inside': async () => {
+      await outputFiles({
+        '.babelrc.json': JSON.stringify({
+          plugins: [
+            [
+              packageName`babel-plugin-module-resolver`,
+              { alias: { '@components': './components' } },
+            ],
+          ],
+        }),
+      })
+
+      const eslintConfig = {
+        rules: {
+          'self/self': [
+            'error',
+            {
+              forSubpaths: {
+                fromInside: true,
+              },
             },
-          },
+          ],
+        },
+      }
+      expect(
+        lint("import foo from './sub/foo'", {
+          eslintConfig,
+          filename: './components/bar.js',
         }),
       ).toEqual({
         messages: [
-          "Unexpected subpath import './sub/foo'. Use '@/sub/foo' instead",
+          "Unexpected subpath import './sub/foo'. Use '@components/sub/foo' instead",
         ],
-        output: "import foo from '@/sub/foo'",
+        output: "import foo from '@components/sub/foo'",
       })
+      expect(
+        lint("import foo from './components/foo'", {
+          eslintConfig,
+        }).messages,
+      ).toEqual([])
+    },
+    'alias for subpaths from outside': async () => {
+      await outputFiles({
+        '.babelrc.json': JSON.stringify({
+          plugins: [
+            [
+              packageName`babel-plugin-module-resolver`,
+              { alias: { '@components': './components' } },
+            ],
+          ],
+        }),
+      })
+
+      const eslintConfig = {
+        rules: {
+          'self/self': [
+            'error',
+            {
+              forSubpaths: {
+                fromOutside: true,
+              },
+            },
+          ],
+        },
+      }
+      expect(
+        lint("import foo from './components/foo'", {
+          eslintConfig,
+        }),
+      ).toEqual({
+        messages: [
+          "Unexpected subpath import './components/foo'. Use '@components/foo' instead",
+        ],
+        output: "import foo from '@components/foo'",
+      })
+      expect(
+        lint("import foo from './sub/foo'", {
+          eslintConfig,
+          filename: './components/bar.js',
+        }).messages,
+      ).toEqual([])
     },
     'alias parent': async () => {
       await outputFiles({