tools: simplify tools/doc/addon-verify.js

Make the script synchronous and clean it up.  This is preparatory work
for follow-ups commits.

PR-URL: nodejs#17407
Reviewed-By: Richard Lau <riclau@uk.ibm.com>

tools/doc/addon-verify.js

@@ -1,5 +1,6 @@
 'use strict';
 
+const { strictEqual } = require('assert');
 const fs = require('fs');
 const path = require('path');
 const marked = require('marked');
@@ -8,52 +9,36 @@ const rootDir = path.resolve(__dirname, '..', '..');
 const doc = path.resolve(rootDir, 'doc', 'api', 'addons.md');
 const verifyDir = path.resolve(rootDir, 'test', 'addons');
 
-const contents = fs.readFileSync(doc).toString();
-
-const tokens = marked.lexer(contents);
 let id = 0;
-
 let currentHeader;
+
 const addons = {};
-tokens.forEach((token) => {
-  if (token.type === 'heading' && token.text) {
-    currentHeader = token.text;
+const content = fs.readFileSync(doc, 'utf8');
+for (const { text, type } of marked.lexer(content)) {
+  if (type === 'heading' && text) {
+    currentHeader = text;
     addons[currentHeader] = {
       files: {}
     };
   }
-  if (token.type === 'code') {
-    var match = token.text.match(/^\/\/\s+(.*\.(?:cc|h|js))[\r\n]/);
+  if (type === 'code') {
+    const match = text.match(/^\/\/\s+(.*\.(?:cc|h|js))[\r\n]/);
     if (match !== null) {
-      addons[currentHeader].files[match[1]] = token.text;
+      addons[currentHeader].files[match[1]] = text;
     }
   }
-});
-for (var header in addons) {
-  verifyFiles(addons[header].files,
-              header,
-              console.log.bind(null, 'wrote'),
-              function(err) { if (err) throw err; });
 }
 
-function once(fn) {
-  var once = false;
-  return function() {
-    if (once)
-      return;
-    once = true;
-    fn.apply(this, arguments);
-  };
-}
+for (const header in addons) {
+  let { files } = addons[header];
 
-function verifyFiles(files, blockName, onprogress, ondone) {
   // must have a .cc and a .js to be a valid test
   if (!Object.keys(files).some((name) => /\.cc$/.test(name)) ||
       !Object.keys(files).some((name) => /\.js$/.test(name))) {
-    return;
+    continue;
   }
 
-  blockName = blockName
+  const blockName = header
     .toLowerCase()
     .replace(/\s/g, '_')
     .replace(/[^a-z\d_]/g, '');
@@ -62,29 +47,17 @@ function verifyFiles(files, blockName, onprogress, ondone) {
     `${(++id < 10 ? '0' : '') + id}_${blockName}`
   );
 
-  files = Object.keys(files).map(function(name) {
-    if (name === 'test.js') {
-      files[name] = `'use strict';
-const common = require('../../common');
-${files[name].replace(
-    "'./build/Release/addon'",
-    // eslint-disable-next-line no-template-curly-in-string
-    '`./build/${common.buildType}/addon`')}
-`;
-    }
-    return {
-      path: path.resolve(dir, name),
-      name: name,
-      content: files[name]
-    };
+  files = Object.entries(files).map(([name, content]) => {
+    if (name === 'test.js') content = boilerplate(name, content);
+    return { name, content, path: path.resolve(dir, name) };
   });
 
   files.push({
     path: path.resolve(dir, 'binding.gyp'),
     content: JSON.stringify({
       targets: [
         {
-          target_name: 'addon',
+          target_name: 'binding',
           defines: [ 'V8_DEPRECATION_WARNINGS=1' ],
           sources: files.map(function(file) {
             return file.name;
@@ -94,22 +67,34 @@ ${files[name].replace(
     })
   });
 
-  fs.mkdir(dir, function() {
-    // Ignore errors
+  try {
+    fs.mkdirSync(dir);
+  } catch (e) {
+    strictEqual(e.code, 'EEXIST');
+  }
 
-    const done = once(ondone);
-    var waiting = files.length;
-    files.forEach(function(file) {
-      fs.writeFile(file.path, file.content, function(err) {
-        if (err)
-          return done(err);
+  for (const file of files) {
+    let content;
+    try {
+      content = fs.readFileSync(file.path, 'utf8');
+    } catch (e) {
+      strictEqual(e.code, 'ENOENT');
+    }
 
-        if (onprogress)
-          onprogress(file.path);
+    // Only update when file content has changed to prevent unneeded rebuilds.
+    if (content !== file.content) {
+      fs.writeFileSync(file.path, file.content);
+      console.log('wrote', file.path);
+    }
+  }
+}
 
-        if (--waiting === 0)
-          done();
-      });
-    });
-  });
+function boilerplate(name, content) {
+  return `'use strict';
+const common = require('../../common');
+${content.replace(
+    "'./build/Release/binding'",
+    // eslint-disable-next-line no-template-curly-in-string
+    '`./build/${common.buildType}/binding`')}
+`;
 }