fix extension handling; closes #3808

lib/cli/options.js

@@ -10,7 +10,8 @@ const fs = require('fs');
 const yargsParser = require('yargs-parser');
 const {types, aliases} = require('./run-option-metadata');
 const {ONE_AND_DONE_ARGS} = require('./one-and-dones');
-const mocharc = require('../mocharc.json');
+// paranoia
+const mocharc = Object.freeze(require('../mocharc.json'));
 const {list} = require('./run-helpers');
 const {loadConfig, findConfig} = require('./config');
 const findUp = require('find-up');
@@ -321,14 +322,38 @@ const loadOptions = (argv = []) => {
     args.opts = false;
     args._ = args._.concat(optsConfig._ || []);
   }
+  // special case: "extension" option should not combine with default value.
+  // normally we want to combine "array"-type options, and we _do_ with "extension", but only
+  // within user-defined configuration (args or anything else).
+  // we must also search through any aliases of "extension" because while the arguments are ///
+  // normalized by this point, the config file values are not.
+  // only the "canonical" option name is used in `mocharc`, so we needn't worry about clearing
+  // multiple options.
+  // NOTE: as of this writing, "extension" is the only default value which is of an "array" type;
+  // it's unknown whether the the below strategy should be generalized to any other future
+  // "array"-type default option.
+  const processedMocharc = Object.assign({}, mocharc);
+  if (
+    args.extension ||
+    ['extension']
+      .concat(aliases.extension)
+      .some(
+        opt =>
+          Object.hasOwnProperty(rcConfig, opt) ||
+          Object.hasOwnProperty(pkgConfig, opt) ||
+          Object.hasOwnProperty(optsConfig, opt)
+      )
+  ) {
+    delete processedMocharc.extension;
+  }
 
   args = parse(
     args._,
     args,
     rcConfig || {},
     pkgConfig || {},
     optsConfig || {},
-    mocharc
+    processedMocharc
   );
 
   // recombine positional arguments and "spec"

lib/utils.js

@@ -575,9 +575,15 @@ exports.lookupFiles = function lookupFiles(filepath, extensions, recursive) {
   var stat;
 
   if (!fs.existsSync(filepath)) {
-    if (fs.existsSync(filepath + '.js')) {
-      filepath += '.js';
-    } else {
+    // check all extensions
+    if (
+      !extensions.some(function(ext) {
+        if (fs.existsSync(filepath + '.' + ext)) {
+          filepath += '.' + ext;
+          return true;
+        }
+      })
+    ) {
       // Handle glob
       files = glob.sync(filepath);
       if (!files.length) {

test/node-unit/cli/options.spec.js

@@ -27,7 +27,9 @@ const defaults = {
   timeout: 1000,
   timeouts: 1000,
   t: 1000,
-  opts: '/default/path/to/mocha.opts'
+  opts: '/default/path/to/mocha.opts',
+  extension: ['js'],
+  'watch-extensions': ['js']
 };
 
 describe('options', function() {
@@ -59,6 +61,7 @@ describe('options', function() {
   describe('loadOptions()', function() {
     describe('when no parameter provided', function() {
       beforeEach(function() {
+        this.timeout(500);
         readFileSync = sandbox.stub();
         readFileSync.onFirstCall().returns('{}');
         readFileSync.onSecondCall().returns('--retries 3');
@@ -497,8 +500,8 @@ describe('options', function() {
           beforeEach(function() {
             readFileSync = sandbox.stub();
             config = '/some/.mocharc.json';
-            readFileSync.onFirstCall().returns('--retries 3');
-            readFileSync.onSecondCall().returns('{}');
+            readFileSync.onFirstCall().returns('{}');
+            readFileSync.onSecondCall().returns('--retries 3');
             findConfig = sandbox.stub();
             loadConfig = sandbox.stub().throws('Error', 'failed to parse');
             findupSync = sandbox.stub().returns('/some/package.json');
@@ -542,8 +545,8 @@ describe('options', function() {
 
             beforeEach(function() {
               readFileSync = sandbox.stub();
-              readFileSync.onFirstCall().returns('--retries 3');
-              readFileSync.onSecondCall().returns('{}');
+              readFileSync.onFirstCall().returns('{}');
+              readFileSync.onSecondCall().throws();
               findConfig = sandbox.stub().returns('/some/.mocharc.json');
               loadConfig = sandbox.stub().returns({});
               findupSync = sandbox.stub().returns('/some/package.json');
@@ -578,8 +581,8 @@ describe('options', function() {
 
             beforeEach(function() {
               readFileSync = sandbox.stub();
-              readFileSync.onFirstCall().returns('--retries 3');
-              readFileSync.onSecondCall().returns('{}');
+              readFileSync.onFirstCall().returns('{}');
+              readFileSync.onSecondCall().throws();
               findConfig = sandbox.stub().returns(null);
               loadConfig = sandbox.stub().returns({});
               findupSync = sandbox.stub().returns('/some/package.json');
@@ -716,5 +719,78 @@ describe('options', function() {
         });
       });
     });
+
+    describe('"extension" handling', function() {
+      describe('when user supplies "extension" option', function() {
+        let result;
+
+        beforeEach(function() {
+          readFileSync = sandbox.stub();
+          readFileSync.onFirstCall().throws();
+          findConfig = sandbox.stub().returns('/some/.mocharc.json');
+          loadConfig = sandbox.stub().returns({extension: ['tsx']});
+          findupSync = sandbox.stub();
+          loadOptions = proxyLoadOptions({
+            readFileSync,
+            findConfig,
+            loadConfig,
+            findupSync
+          });
+          result = loadOptions(['--extension', 'ts']);
+        });
+
+        it('should not concatenate the default value', function() {
+          expect(result, 'to have property', 'extension', ['ts', 'tsx']);
+        });
+      });
+
+      describe('when user does not supply "extension" option', function() {
+        let result;
+
+        beforeEach(function() {
+          readFileSync = sandbox.stub();
+          readFileSync.onFirstCall().throws();
+          findConfig = sandbox.stub().returns('/some/.mocharc.json');
+          loadConfig = sandbox.stub().returns({});
+          findupSync = sandbox.stub();
+          loadOptions = proxyLoadOptions({
+            readFileSync,
+            findConfig,
+            loadConfig,
+            findupSync
+          });
+          result = loadOptions();
+        });
+
+        it('should retain the default', function() {
+          expect(result, 'to have property', 'extension', ['js']);
+        });
+      });
+    });
+
+    describe('"spec" handling', function() {
+      describe('when user supplies "spec" in config and positional arguments', function() {
+        let result;
+
+        beforeEach(function() {
+          readFileSync = sandbox.stub();
+          readFileSync.onFirstCall().throws();
+          findConfig = sandbox.stub().returns('/some/.mocharc.json');
+          loadConfig = sandbox.stub().returns({spec: '*.spec.js'});
+          findupSync = sandbox.stub();
+          loadOptions = proxyLoadOptions({
+            readFileSync,
+            findConfig,
+            loadConfig,
+            findupSync
+          });
+          result = loadOptions(['*.test.js']);
+        });
+
+        it('should place both into the positional arguments array', function() {
+          expect(result, 'to have property', '_', ['*.test.js', '*.spec.js']);
+        });
+      });
+    });
   });
 });