Test run list proposal (#7617)

* Test run list propsal

* fixed ts errors

* added js file

* excluding testSetup.js file from hygiene

* moved ignore line to indententationFilter

build/testSetup.js

@@ -0,0 +1,57 @@
+"use strict";
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+const fs = require('fs').promises;
+const path = require('path');
+const readConfiguration = (async () => {
+    const parseConfigString = ((content) => {
+        try {
+            const result = JSON.parse(content);
+            return result;
+        }
+        catch (ex) {
+            console.log('Could NOT parse TEST_RUN_LIST:', content);
+        }
+    });
+    // Attempt to read from an enviornment variable
+    const testRunlist = process.env['TEST_RUN_LIST'];
+    if (testRunlist && testRunlist !== '') {
+        const result = parseConfigString(testRunlist);
+        if (result) {
+            console.log('Using the environment test run list:', result);
+            return result;
+        }
+    }
+    // Attempt to read from a config file
+    let testRunPath = process.env['TEST_RUN_LIST_FILE'];
+    if (!testRunPath || testRunPath === '') {
+        testRunPath = path.resolve(__dirname, '..', 'runlist.json');
+    }
+    try {
+        const contents = await fs.readFile(testRunPath);
+        return parseConfigString(contents);
+    }
+    catch (ex) {
+        console.log(`error reading file ${testRunPath}:`, ex);
+    }
+});
+(async () => {
+    const keys = process.argv.slice(2);
+    const configuration = await readConfiguration();
+    if (!configuration) {
+        console.log('no configuration was setup');
+        return;
+    }
+    const testList = [];
+    keys.forEach((key) => {
+        const arr = configuration[key];
+        if (arr) {
+            testList.push(...arr);
+        }
+    });
+    const result = `(${testList.join('|')})`;
+    console.log(result);
+    process.env['TEST_GREP'] = result;
+})();