doc,tools: get altDocs versions from CHANGELOG.md

Parse `CHANGELOG.md` for versions of Node.js used by the documentation feature `View another version` so that we don't have to manually update the list when we cut a new version or transition a release to LTS. Backport-PR-URL: #32642 PR-URL: #27661 Reviewed-By: Rich Trott <[email protected]>

Author: richardlau

test/internet/test-doctool-versions.js

@@ -0,0 +1,59 @@
+'use strict';
+
+require('../common');
+constassert=require('assert');
+constutil=require('util');
+const{ versions }=require('../../tools/doc/versions.js');
+
+// At the time of writing these are the minimum expected versions.
+// New versions of Node.js do not have to be explicitly added here.
+constexpected=[
+'12.x',
+'11.x',
+'10.x',
+'9.x',
+'8.x',
+'7.x',
+'6.x',
+'5.x',
+'4.x',
+'0.12.x',
+'0.10.x',
+];
+
+asyncfunctiontest(){
+constvers=awaitversions();
+// Coherence checks for each returned version.
+for(constversionofvers){
+consttested=util.inspect(version);
+constparts=version.num.split('.');
+constexpectedLength=parts[0]==='0' ? 3 : 2;
+assert.strictEqual(parts.length,expectedLength,
+`'num' from ${tested} should be '<major>.x'.`);
+assert.strictEqual(parts[parts.length-1],'x',
+`'num' from ${tested} doesn't end in '.x'.`);
+constisEvenRelease=Number.parseInt(parts[expectedLength-2])%2===0;
+consthasLtsProperty=version.hasOwnProperty('lts');
+if(hasLtsProperty){
+// Odd-numbered versions of Node.js are never LTS.
+assert.ok(isEvenRelease,`${tested} should not be an 'lts' release.`);
+assert.ok(version.lts,`'lts' from ${tested} should 'true'.`);
+}
+}
+
+// Check that the minimum number of versions were returned.
+// Later versions are allowed, but not checked for here (they were checked
+// above).
+// Also check for the previous semver major -- From master this will be the
+// most recent major release.
+constthisMajor=Number.parseInt(process.versions.node.split('.')[0]);
+constprevMajorString=`${thisMajor-1}.x`;
+if(!expected.includes(prevMajorString)){
+expected.unshift(prevMajorString);
+}
+for(constversionofexpected){
+assert.ok(vers.find((x)=>x.num===version),
+`Did not find entry for '${version}' in ${util.inspect(vers)}`);
+}
+}
+test();

tools/doc/html.js

@@ -23,6 +23,7 @@
 
 constcommon=require('./common.js');
 constfs=require('fs');
+constgetVersions=require('./versions.js');
 constunified=require('unified');
 constfind=require('unist-util-find');
 constvisit=require('unist-util-visit');
@@ -62,7 +63,7 @@ const gtocHTML = unified()
 consttemplatePath=path.join(docPath,'template.html');
 consttemplate=fs.readFileSync(templatePath,'utf8');
 
-functiontoHTML({ input, content, filename, nodeVersion },cb){
+asyncfunctiontoHTML({ input, content, filename, nodeVersion },cb){
 filename=path.basename(filename,'.md');
 
 constid=filename.replace(/\W+/g,'-');
@@ -80,7 +81,7 @@ function toHTML({input, content, filename, nodeVersion }, cb){
 constdocCreated=input.match(
 /<!--\s*introduced_in\s*=\s*v([0-9]+)\.([0-9]+)\.[0-9]+\s*-->/);
 if(docCreated){
-HTML=HTML.replace('__ALTDOCS__',altDocs(filename,docCreated));
+HTML=HTML.replace('__ALTDOCS__',awaitaltDocs(filename,docCreated));
 }else{
 console.error(`Failed to add alternative version links to ${filename}`);
 HTML=HTML.replace('__ALTDOCS__','');
@@ -380,22 +381,10 @@ function getId(text, idCounters){
 returntext;
 }
 
-functionaltDocs(filename,docCreated){
+asyncfunctionaltDocs(filename,docCreated){
 const[,docCreatedMajor,docCreatedMinor]=docCreated.map(Number);
 consthost='https://nodejs.org';
-constversions=[
-{num: '12.x'},
-{num: '11.x'},
-{num: '10.x',lts: true},
-{num: '9.x'},
-{num: '8.x',lts: true},
-{num: '7.x'},
-{num: '6.x'},
-{num: '5.x'},
-{num: '4.x'},
-{num: '0.12.x'},
-{num: '0.10.x'}
-];
+constversions=awaitgetVersions.versions();
 
 constgetHref=(versionNum)=>
 `${host}/docs/latest-v${versionNum}/api/${filename}.html`;

tools/doc/versions.js

@@ -0,0 +1,45 @@
+'use strict';
+
+let_versions;
+
+constgetUrl=(url)=>{
+returnnewPromise((resolve,reject)=>{
+consthttps=require('https');
+constrequest=https.get(url,(response)=>{
+if(response.statusCode!==200){
+reject(newError(
+`Failed to get ${url}, status code ${response.statusCode}`));
+}
+response.setEncoding('utf8');
+letbody='';
+response.on('data',(data)=>body+=data);
+response.on('end',()=>resolve(body));
+});
+request.on('error',(err)=>reject(err));
+});
+};
+
+module.exports={
+asyncversions(){
+if(_versions){
+return_versions;
+}
+
+// The CHANGELOG.md on release branches may not reference newer semver
+// majors of Node.js so fetch and parse the version from the master branch.
+constgithubContentUrl='https://raw.githubusercontent.com/nodejs/node/';
+constchangelog=awaitgetUrl(`${githubContentUrl}/master/CHANGELOG.md`);
+constltsRE=/LongTermSupport/i;
+constversionRE=/\*\[Node\.js([0-9.]+)\][^-—]+[-—]\s*(.*)\n/g;
+_versions=[];
+letmatch;
+while((match=versionRE.exec(changelog))!=null){
+constentry={num: `${match[1]}.x`};
+if(ltsRE.test(match[2])){
+entry.lts=true;
+}
+_versions.push(entry);
+}
+return_versions;
+}
+};