replace mocha dependency (#3131)

package.json

@@ -28,7 +28,7 @@
   },
   "devDependencies": {
     "acorn": "~5.5.3",
-    "mocha": "~3.5.1",
+    "colors": "~1.2.5",
     "semver": "~5.5.0"
   },
   "scripts": {

test/mocha.js

@@ -1,24 +1,102 @@
+var colors = require("colors");
 var fs = require("fs");
-var Mocha = require("mocha");
-var path = require("path");
 
-// Instantiate a Mocha instance
-var mocha = new Mocha({
-    timeout: 5000
-});
-var testDir = __dirname + "/mocha/";
+var config = {
+    limit: 5000,
+    timeout: function(limit) {
+        this.limit = limit;
+    }
+};
+var tasks = [];
+var titles = [];
+describe = function(title, fn) {
+    config = Object.create(config);
+    titles.push(title);
+    fn.call(config);
+    titles.pop();
+    config = Object.getPrototypeOf(config);
+};
+it = function(title, fn) {
+    fn.limit = config.limit;
+    fn.titles = titles.slice();
+    fn.titles.push(title);
+    tasks.push(fn);
+};
 
-// Add each .js file to the Mocha instance
-fs.readdirSync(testDir).filter(function(file) {
+fs.readdirSync("test/mocha").filter(function(file) {
     return /\.js$/.test(file);
 }).forEach(function(file) {
-    mocha.addFile(path.join(testDir, file));
+    require("./mocha/" + file);
 });
 
-module.exports = function() {
-    mocha.run(function(failures) {
-        if (failures) process.on("exit", function() {
-            process.exit(failures);
-        });
-    });
+function log_titles(log, current, marker) {
+    var indent = "";
+    var writing = false;
+    for (var i = 0; i < current.length; i++, indent += "  ") {
+        if (titles[i] != current[i]) writing = true;
+        if (writing) log(indent + (i == current.length - 1 && marker || "") + current[i]);
+    }
+    titles = current;
+}
+
+var errors = [];
+var total = tasks.length;
+titles = [];
+process.nextTick(function run() {
+    var task = tasks.shift();
+    if (task) try {
+        var elapsed = Date.now();
+        var timer;
+        var done = function() {
+            clearTimeout(timer);
+            done = function() {};
+            elapsed = Date.now() - elapsed;
+            if (elapsed > task.limit) {
+                throw new Error("Timed out: " + elapsed + "ms > " + task.limit + "ms");
+            }
+            log_titles(console.log, task.titles, colors.green('\u221A '));
+            process.nextTick(run);
         };
+        if (task.length) {
+            task.timeout = function(limit) {
+                clearTimeout(timer);
+                task.limit = limit;
+                timer = setTimeout(function() {
+                    raise(new Error("Timed out: exceeds " + limit + "ms"));
+                }, limit);
+            };
+            task.timeout(task.limit);
+            task.call(task, done);
+        } else {
+            task.timeout = config.timeout;
+            task.call(task);
+            done();
+        }
+    } catch (err) {
+        raise(err);
+    } else if (errors.length) {
+        console.error();
+        console.log(colors.red(errors.length + " test(s) failed!"));
+        titles = [];
+        errors.forEach(function(titles, index) {
+            console.error();
+            log_titles(console.error, titles, (index + 1) + ") ");
+            var lines = titles.error.stack.split('\n');
+            console.error(colors.red(lines[0]));
+            console.error(lines.slice(1).join("\n"));
+        });
+        process.exit(1);
+    } else {
+        console.log();
+        console.log(colors.green(total + " test(s) passed."));
+    }
+
+    function raise(err) {
+        clearTimeout(timer);
+        done = function() {};
+        task.titles.error = err;
+        errors.push(task.titles);
+        log_titles(console.log, task.titles, colors.red('\u00D7 '));
+        process.nextTick(run);
+    }
+});

test/run-tests.js

@@ -18,9 +18,8 @@ if (failures) {
     console.error("!!! " + Object.keys(failed_files).join(", "));
     process.exit(1);
 }
-
-var mocha_tests = require("./mocha.js");
-mocha_tests();
+console.log();
+require("./mocha.js");
 
 /* -----[ utils ]----- */