Adds ability to support array of alias values.

README.md

@@ -47,7 +47,8 @@ module.exports = {
           ['babel-polyfill', 'babel-polyfill/dist/polyfill.min.js'],
           ['helper', './utils/helper'],
           ['material-ui/DatePicker', '../custom/DatePicker'],
-          ['material-ui', 'material-ui-ie10']
+          ['material-ui', 'material-ui-ie10'],
+          ['lib', ['app/lib', 'common/lib']]
         ],
         extensions: ['.ts', '.js', '.jsx', '.json']
       }
@@ -62,6 +63,7 @@ Note:
 - The item of `map` array is also array type which contains 2 string
     + The first string represents the alias of module name or path
     + The second string represents the actual module name or path
+    + The second string may also be an array that is evaluated in order, with the first found used as resolved
 - The `map` item `['helper', './utils/helper']` means that the modules which match `helper` or `helper/*` will be resolved to `./utils/helper` or `./utils/helper/*` which are located relative to the `process current working directory` (almost the project root directory). If you just want to resolve `helper` to `./utils/helper`, use `['^helper$', './utils/helper']` instead. See [issue #3](https://github.com/johvin/eslint-import-resolver-alias/issues/3)
 - The order of 'material-ui/DatePicker' and 'material-ui' cannot be reversed, otherwise the alias rule 'material-ui/DatePicker' does not work
 - The default value of `extensions` property is `['.js', '.json', '.node']` if it is assigned to an empty array or not specified

index.js

@@ -58,23 +58,39 @@ exports.resolve = (modulePath, sourceFile, config) => {
       const re = new RegExp(`^${map[i][0]}($|/)`);
       const match = modulePath.match(re);
       if (match) {
-        resolvePath = modulePath.replace(match[0], `${map[i][1]}${match[1]}`);
+        resolvePath = getResolvePath(modulePath, match, map[i][1], extensions, sourceDir);
         break;
       }
     }
   }
 
-  // there is a relative path mapping in alias.map,
-  // the relative path is relative to the project root directory
-  if (resolvePath[0] === '.') {
-    resolvePath = path.resolve(process.cwd(), resolvePath);
-    return findModulePath(resolvePath, null, extensions);
-  }
-
-  const paths = resolveLookupPaths(sourceDir);
-  return findModulePath(resolvePath, paths, extensions);
+  return smartFindModulePath(resolvePath, extensions, sourceDir);
 };
 
+// Get the resolved path
+function getResolvePath(alias, match, actual, extensions, sourceDir) {
+  if (Array.isArray(actual)) {
+    let resolvePath, found;
+
+    // Iterate through all possible paths
+    for (let i = 0; i < actual.length; i++) {
+      resolvePath = alias.replace(match[0], `${actual[i]}${match[1]}`);
+      found = smartFindModulePath(resolvePath, extensions, sourceDir);
+
+      // If path resolves, use it, don't check any more
+      if (found.found) {
+        return resolvePath;
+      }
+    }
+
+    // If no paths resolve, still return final path, we want to know if no paths resolve
+    return resolvePath;
+  }
+  else {
+    return alias.replace(match[0], `${actual}${match[1]}`);
+  }
+}
+
 // get extension object like Module._extensions
 function getExtensions(extArray) {
   if (Array.isArray(extArray) && extArray.length > 0) {
@@ -87,6 +103,19 @@ function getExtensions(extArray) {
   return null;
 }
 
+// Find module path, taking into account relative paths
+function smartFindModulePath(resolvePath, extensions, sourceDir) {
+  // there is a relative path mapping in alias.map,
+  // the relative path is relative to the project root directory
+  if (resolvePath[0] === '.') {
+    resolvePath = path.resolve(process.cwd(), resolvePath);
+    return findModulePath(resolvePath, null, extensions);
+  }
+
+  const paths = resolveLookupPaths(sourceDir);
+  return findModulePath(resolvePath, paths, extensions);
+}
+
 // find module path according to support file extensions.
 function findModulePath(request, paths, extArray) {
   if (extArray) {

test/setup.js

@@ -14,7 +14,9 @@ const files = [
   `${moduleDir}/module2/smile.js`,
   `${moduleDir}/module2/nav.jsx`,
   `${moduleDir}/polyfill2/polyfill.min.js`,
-  `${moduleDir}/mod/a.js`
+  `${moduleDir}/has_abc/abc.js`,
+  `${moduleDir}/has_def/def.js`,
+  `${moduleDir}/mod/a.js`,
 ];
 
 files.forEach(file => {

test/test.js

@@ -14,7 +14,8 @@ describe('resolver-alias/index.js', () => {
       ['red', './nothing'], // should not impact the paths which contain red and not starts with red
       ['module3', 'module2'],
       ['srcCore', './core'],
-      ['relativeSetup', './test/setup']
+      ['relativeSetup', './test/setup'],
+      ['arrayPaths', ['has_abc', 'has_none', 'has_def']],
     ],
     extensions: ['.js', '.ts', '.jsx', '.json']
   };
@@ -43,6 +44,16 @@ describe('resolver-alias/index.js', () => {
     'srcCore',
     'relativeSetup'
   ];
+  const aliasModuleArrayPathArr = [
+    'module3/heihei',
+    'module3/styles/red',
+    'module3/nav',
+    'polyfill',
+    'core/red',
+    'core',
+    'arrayPaths/abc',
+    'arrayPaths/def',
+  ];
   const noneExistModulePathArr = [
     'abc/ggg',
     'module2/bye',
@@ -132,6 +143,18 @@ describe('resolver-alias/index.js', () => {
     });
   });
 
+  it('resolve alias modules that have an array of actual modules or paths', () => {
+    aliasModuleArrayPathArr.forEach((p) => {
+      const resolveModule = resolver.resolve(p, sourceFile, alias);
+      assert(resolveModule.found, `alias modulePath ${p} isn't resolved`);
+    });
+  });
+
+  it('unable to resolve array modules that do not exist', () => {
+    const resolveModule = resolver.resolve('arrayPaths/ghi', sourceFile, alias);
+    assert(!resolveModule.found, `alias modulePath arrayPaths/ghi is resolved`);
+  });
+
   it('unable to resolve the modules that do not exist', () => {
     noneExistModulePathArr.forEach((p) => {
       const resolveModule = resolver.resolve(p, sourceFile, alias);
@@ -154,5 +177,4 @@ describe('resolver-alias/index.js', () => {
     const a = require('mod/a');
     assert(a.abc.found && a.abc.path != null, 'exist module is not resolved');
   });
-
 });