Modernize internal JS code and run it through eslint. NFC (#15845)

This change does not effect the JS that we output, only the the internal
JS tooling.

This is a followup to #15836 which did this cleanup just for a single
file.

The long list of exclusions in `.eslintrc.yml` is because these files
are part of the JS library code which we ship and we a lot of that
cannot be run though the lint tool because it uses our speciall
pre-processing techniques.

Author: sbc100

.eslintrc.yml

@@ -6,7 +6,48 @@ extends:
   - google
 parserOptions:
   ecmaVersion: 12
-ignorePatterns: "library_*.js"
+ignorePatterns:
+  - "site/"
+  - "third_party/"
+  - "tests/"
+  - "src/library*.js"
+  - "src/runtime_*.js"
+  - "src/shell*.js"
+  - "src/preamble*.js"
+  - "src/postamble*.js"
+  - "src/closure-externs/"
+  - "src/embind/"
+  - "src/emrun_postjs.js"
+  - "src/worker.js"
+  - "src/wrtcp.js"
+  - "src/wasm2js.js"
+  - "src/webGLClient.js"
+  - "src/webGLWorker.js"
+  - "src/*_shell_read.js"
+  - "src/wasm_offset_converter.js"
+  - "src/threadprofiler.js"
+  - "src/cpuprofiler.js"
+  - "src/memoryprofiler.js"
+  - "src/support.js"
+  - "src/gl-matrix.js"
+  - "src/promise_polyfill.js"
+  - "src/headless.js"
+  - "src/headlessCanvas.js"
+  - "src/socket.io.js"
+  - "src/emscripten-source-map.min.js"
+  - "src/source_map_support.js"
+  - "src/Fetch.js"
+  - "src/settings.js"
+  - "src/settings_internal.js"
+  - "src/arrayUtils.js"
+  - "src/deterministic.js"
+  - "src/base64Utils.js"
+  - "src/base64Decode.js"
+  - "src/proxyWorker.js"
+  - "src/proxyClient.js"
+  - "src/IDBStore.js"
+  - "src/URIUtils.js"
+  - "tools/experimental"
 rules:
   #max-len: ["error", 100]
   max-len: "off"

package.json

@@ -14,6 +14,6 @@
     "wasm2c": "1.0.0"
   },
   "scripts": {
-    "lint": "eslint src/parseTools.js tools/acorn-optimizer.js tools/lz4-compress.js"
+    "lint": "eslint ."
   }
 }

src/minimal_runtime_worker_externs.js renamed to src/closure-externs/minimal_runtime_worker_externs.js

@@ -7,30 +7,30 @@
 
 // LLVM => JavaScript compiler, main entry point
 
-var nodeFS = require('fs');
-nodePath = require('path');
+global.nodeFS = require('fs');
+global.nodePath = require('path');
 
-print = (x) => {
+global.print = (x) => {
   process['stdout'].write(x + '\n');
 };
 
-printErr = (x) => {
+global.printErr = (x) => {
   process['stderr'].write(x + '\n');
 };
 
 function find(filename) {
-  var prefixes = [__dirname, process.cwd()];
-  for (var i = 0; i < prefixes.length; ++i) {
-    var combined = nodePath.join(prefixes[i], filename);
+  const prefixes = [__dirname, process.cwd()];
+  for (let i = 0; i < prefixes.length; ++i) {
+    const combined = nodePath.join(prefixes[i], filename);
     if (nodeFS.existsSync(combined)) {
       return combined;
     }
   }
   return filename;
 }
 
-read = (filename) => {
-  var absolute = find(filename);
+global.read = (filename) => {
+  const absolute = find(filename);
   return nodeFS.readFileSync(absolute).toString();
 };
 
@@ -45,22 +45,23 @@ load('utility.js');
 load('./settings.js');
 load('./settings_internal.js');
 
-var arguments_ = process['argv'].slice(2);
-var settingsFile = arguments_[0];
+const settingsFile = process['argv'][2];
 
 if (settingsFile) {
-  var settings = JSON.parse(read(settingsFile));
-  for (var key in settings) {
-    var value = settings[key];
-    if (value[0] == '@') {
-      // response file type thing, workaround for large inputs: value is @path-to-file
-      try {
-        value = JSON.parse(read(value.substr(1)));
-      } catch(e) {
-        // continue normally; assume it is not a response file
+  const settings = JSON.parse(read(settingsFile));
+  for (const key in settings) {
+    if (Object.prototype.hasOwnProperty.call(settings, key)) {
+      let value = settings[key];
+      if (value[0] == '@') {
+        // response file type thing, workaround for large inputs: value is @path-to-file
+        try {
+          value = JSON.parse(read(value.substr(1)));
+        } catch (e) {
+          // continue normally; assume it is not a response file
+        }
       }
+      global[key] = eval(JSON.stringify(value));
     }
-    global[key] = eval(JSON.stringify(value));
   }
 }
 
@@ -72,7 +73,7 @@ INCOMING_MODULE_JS_API = new Set(INCOMING_MODULE_JS_API);
 RUNTIME_DEBUG = LIBRARY_DEBUG || GL_DEBUG || DYLINK_DEBUG || PTHREADS_DEBUG;
 
 // Side modules are pure wasm and have no JS
-assert(!SIDE_MODULE, "JS compiler should not run on side modules");
+assert(!SIDE_MODULE, 'JS compiler should not run on side modules');
 
 // Output some info and warnings based on settings
 
@@ -87,17 +88,17 @@ load('parseTools.js');
 load('jsifier.js');
 load('runtime.js');
 
-//===============================
+// ===============================
 // Main
-//===============================
+// ===============================
 
 B = new Benchmarker();
 
 try {
-  JSify();
+  runJSify();
 
   B.print('glue');
-} catch(err) {
+} catch (err) {
   if (err.toString().includes('Aborting compilation due to previous errors')) {
     // Compiler failed on user error, don't print the stacktrace in this case.
     printErr(err);

src/compiler.js

@@ -5,7 +5,7 @@
  */
 
 // Route URL GET parameters to argc+argv
-if (typeof window === "object") {
+if (typeof window === 'object') {
   Module['arguments'] = window.location.search.substr(1).trim().split('&');
   // If no args were passed arguments = [''], in which case kill the single empty string.
   if (!Module['arguments'][0]) {