Adds failed test tracking

scripts/failed-tests.js

@@ -0,0 +1,117 @@
+// @ts-check
+const Mocha = require("mocha");
+const path = require("path");
+const fs = require("fs");
+const os = require("os");
+
+/**
+ * .failed-tests reporter
+ * 
+ * @typedef {Object} ReporterOptions
+ * @property {string} [file]
+ * @property {boolean} [keepFailed]
+ * @property {string|Mocha.ReporterConstructor} [reporter]
+ * @property {*} [reporterOptions]
+ */
+class FailedTestsReporter extends Mocha.reporters.Base {
+    /**
+     * @param {Mocha.Runner} runner 
+     * @param {{ reporterOptions?: ReporterOptions }} [options]
+     */
+    constructor(runner, options) {
+        super(runner, options);
+        if (!runner) return;
+
+        const reporterOptions = this.reporterOptions = options.reporterOptions || {};
+        if (reporterOptions.file === undefined) reporterOptions.file = ".failed-tests";
+        if (reporterOptions.keepFailed === undefined) reporterOptions.keepFailed = false;
+        if (reporterOptions.reporter) {
+            /** @type {Mocha.ReporterConstructor} */
+            let reporter;
+            if (typeof reporterOptions.reporter === "function") {
+                reporter = reporterOptions.reporter;
+            }
+            else if (Mocha.reporters[reporterOptions.reporter]) {
+                reporter = Mocha.reporters[reporterOptions.reporter];
+            }
+            else {
+                try {
+                    reporter = require(reporterOptions.reporter);
+                }
+                catch (_) {
+                    reporter = require(path.resolve(process.cwd(), reporterOptions.reporter));
+                }
+            }
+
+            const newOptions = Object.assign({}, options, { reporterOptions: reporterOptions.reporterOptions || {} });
+            this.reporter = new reporter(runner, newOptions);
+        }
+
+        /** @type {Mocha.Test[]} */
+        this.passes = [];
+        
+        /** @type {Mocha.Test[]} */
+        this.failures = [];
+        
+        runner.on("pass", test => this.passes.push(test));
+        runner.on("fail", test => this.failures.push(test));
+    }
+
+    /**
+     * @param {string} file 
+     * @param {ReadonlyArray<Mocha.Test>} passes 
+     * @param {ReadonlyArray<Mocha.Test>} failures 
+     * @param {boolean} keepFailed 
+     * @param {(err?: NodeJS.ErrnoException) => void} done 
+     */
+    static writeFailures(file, passes, failures, keepFailed, done) {
+        const failingTests = new Set(fs.existsSync(file) ? readTests() : undefined);
+        if (failingTests.size > 0) {
+            for (const test of passes) {
+                const title = test.fullTitle().trim();
+                if (title) failingTests.delete(title);
+            }
+        }
+        for (const test of failures) {
+            const title = test.fullTitle().trim();
+            if (title) failingTests.add(title);
+        }
+        if (failingTests.size > 0) {
+            const failed = Array.from(failingTests).join(os.EOL);
+            fs.writeFile(file, failed, "utf8", done);
+        }
+        else if (!keepFailed) {
+            fs.unlink(file, done);
+        }
+        else {
+            done();
+        }
+
+        function readTests() {
+            return fs.readFileSync(file, "utf8")
+                .split(/\r?\n/g)
+                .map(line => line.trim())
+                .filter(line => line.length > 0);
+        }
+    }
+
+    /**
+     * @param {number} failures 
+     * @param {(failures: number) => void} [fn]
+     */
+    done(failures, fn) {
+        FailedTestsReporter.writeFailures(this.reporterOptions.file, this.passes, this.failures, this.reporterOptions.keepFailed || this.stats.tests === 0, (err) => {
+            const reporter = this.reporter;
+            if (reporter && reporter.done) {
+                reporter.done(failures, fn);
+            }
+            else if (fn) {
+                fn(failures);
+            }
+
+            if (err) console.error(err);
+        });
+    }
+}
+
+module.exports = FailedTestsReporter;