tools: doc: improve async workflow of generate.js

Use fs.promises for read and write file
Use unified().process wich is async instead processSync
html and json are write in parallel
errors are logged and exit process with `1` code
Fixes: #30090
PR-URL: #30106
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>

Author: tpoisseau

tools/doc/generate.js

@@ -21,7 +21,7 @@
 
 'use strict';
 
-constfs=require('fs');
+const{promises: fs}=require('fs');
 constpath=require('path');
 constunified=require('unified');
 constmarkdown=require('remark-parse');
@@ -41,36 +41,35 @@ let nodeVersion = null;
 letoutputDir=null;
 letapilinks={};
 
-args.forEach((arg)=>{
-if(!arg.startsWith('--')){
-filename=arg;
-}elseif(arg.startsWith('--node-version=')){
-nodeVersion=arg.replace(/^--node-version=/,'');
-}elseif(arg.startsWith('--output-directory=')){
-outputDir=arg.replace(/^--output-directory=/,'');
-}elseif(arg.startsWith('--apilinks=')){
-constlinkFile=arg.replace(/^--apilinks=/,'');
-constdata=fs.readFileSync(linkFile,'utf8');
-if(!data.trim()){
-thrownewError(`${linkFile} is empty`);
+asyncfunctionmain(){
+for(constargofargs){
+if(!arg.startsWith('--')){
+filename=arg;
+}elseif(arg.startsWith('--node-version=')){
+nodeVersion=arg.replace(/^--node-version=/,'');
+}elseif(arg.startsWith('--output-directory=')){
+outputDir=arg.replace(/^--output-directory=/,'');
+}elseif(arg.startsWith('--apilinks=')){
+constlinkFile=arg.replace(/^--apilinks=/,'');
+constdata=awaitfs.readFile(linkFile,'utf8');
+if(!data.trim()){
+thrownewError(`${linkFile} is empty`);
+}
+apilinks=JSON.parse(data);
 }
-apilinks=JSON.parse(data);
 }
-});
 
-nodeVersion=nodeVersion||process.version;
-
-if(!filename){
-thrownewError('No input file specified');
-}elseif(!outputDir){
-thrownewError('No output directory specified');
-}
+nodeVersion=nodeVersion||process.version;
 
+if(!filename){
+thrownewError('No input file specified');
+}elseif(!outputDir){
+thrownewError('No output directory specified');
+}
 
-fs.readFile(filename,'utf8',async(er,input)=>{
-if(er)thrower;
+constinput=awaitfs.readFile(filename,'utf8');
 
-constcontent=unified()
+constcontent=awaitunified()
 .use(markdown)
 .use(html.preprocessText)
 .use(json.jsonAPI,{ filename })
@@ -80,14 +79,40 @@ fs.readFile(filename, 'utf8', async (er, input) => {
 .use(remark2rehype,{allowDangerousHTML: true})
 .use(raw)
 .use(htmlStringify)
-.processSync(input);
-
-constbasename=path.basename(filename,'.md');
+.process(input);
 
 constmyHtml=awaithtml.toHTML({ input, content, filename, nodeVersion });
+constbasename=path.basename(filename,'.md');
 consthtmlTarget=path.join(outputDir,`${basename}.html`);
-fs.writeFileSync(htmlTarget,myHtml);
-
 constjsonTarget=path.join(outputDir,`${basename}.json`);
-fs.writeFileSync(jsonTarget,JSON.stringify(content.json,null,2));
-});
+
+returnPromise.allSettled([
+fs.writeFile(htmlTarget,myHtml),
+fs.writeFile(jsonTarget,JSON.stringify(content.json,null,2)),
+]);
+}
+
+main()
+.then((tasks)=>{
+// Filter rejected tasks
+consterrors=tasks.filter(({ status })=>status==='rejected')
+.map(({ reason })=>reason);
+
+// Log errors
+for(consterroroferrors){
+console.error(error);
+}
+
+// Exit process with code 1 if some errors
+if(errors.length>0){
+returnprocess.exit(1);
+}
+
+// Else with code 0
+process.exit(0);
+})
+.catch((error)=>{
+console.error(error);
+
+process.exit(1);
+});

tools/doc/package.json

@@ -4,7 +4,7 @@
 "description": "Internal tool for generating Node.js API docs",
 "version": "0.0.0",
 "engines": {
-"node": ">=6"
+"node": ">=12.10.0"
  },
 "dependencies": {
 "rehype-raw": "^2.0.0",