Add support for running test-js-with-node on particular files.

Fixed: #1127.

README.dev.md

@@ -1311,7 +1311,7 @@ time debugging a test failure, e.g.:
 ./tools/lint-all # Runs all the linters in parallel
 ./tools/test-backend zerver.tests.test_bugdown.BugdownTest.test_inline_youtube
 ./tools/test-js-with-casper 09-navigation.js
-./tools/test-js-with-node # Runs all node tests but is very fast
+./tools/test-js-with-node util.js
 ```
 
 The above setup instructions include the first-time setup of test

docs/testing.md

@@ -27,7 +27,7 @@ time debugging a test failure, e.g.:
 ./tools/lint-all # Runs all the linters in parallel
 ./tools/test-backend zerver.tests.test_bugdown.BugdownTest.test_inline_youtube
 ./tools/test-js-with-casper 09-navigation.js
-./tools/test-js-with-node # Runs all node tests but is very fast
+./tools/test-js-with-node utils.js
 ```
 
 ### Schema and initial data changes

frontend_tests/node_tests/index.js

@@ -10,13 +10,27 @@ var _ = global._;
 // Run all the JS scripts in our test directory.  Tests do NOT run
 // in isolation.
 
+var oneFileFilter = [];
+var testsDifference = [];
+if (process.argv[2] ) {
+    oneFileFilter = process.argv
+      .slice(2)
+      .map(function (filename) {return filename.replace(/\.js$/i, '');});
+}
+
 var tests = fs.readdirSync(__dirname)
   .filter(function (filename) {return (/\.js$/i).test(filename);})
   .map(function (filename) {return filename.replace(/\.js$/i, '');});
 
-
+if (oneFileFilter.length > 0) {
+    tests = tests.filter(function (filename) {
+        return oneFileFilter.indexOf(filename) !== -1;
+    });
+    testsDifference = _.difference(oneFileFilter, tests);
+}
 tests.sort();
 
+
 var dependencies = [];
 var old_builtins = {};
 
@@ -109,4 +123,13 @@ tests.forEach(function (filename) {
     old_builtins = {};
 });
 
+if (oneFileFilter.length > 0 && testsDifference.length > 0) {
+    testsDifference.forEach(function (filename) {
+        console.log(filename + " does not exist");
+    });
+    if (oneFileFilter.length > testsDifference.length) {
         console.info("To see more output, open " + output_fn);
+    }
+} else {
+    console.info("To see more output, open " + output_fn);
+}

tools/test-js-with-node

@@ -10,8 +10,17 @@ NODEJS=$(which nodejs || which node)
 if [ "$1" = "cover" ]; then
   # Run a coverage test with Istanbul.
   istanbul cover "$INDEX_JS"
+
+elif [ "$1" = "-h" -o "$1" = "--help" ]; then
+  echo "Usage:
+`basename $0`                      - to run all tests
+`basename $0` util.js              - to run tests from util.js
+`basename $0` util.js activity.js  - to run tests from util.js and activity.js
+"
+  exit 0
+
 else
   # Normal testing, no coverage analysis.
   # Run the index.js test runner, which runs all the other tests.
-  "$NODEJS" --stack-trace-limit=100 "$INDEX_JS"
+  "$NODEJS" --stack-trace-limit=100 "$INDEX_JS" $@
 fi