Merge pull request #13 from devanshj/master

feat: fetch grammar from upstream

Author: urish

.gitignore

@@ -1,8 +1,4 @@
 node_modules
 dist
-src/parser/JavaParser.ts
-src/parser/JavaParserListener.ts
-src/parser/JavaParserVisitor.ts
-src/parser/JavaLexer.ts
-src/parser/JavaContexts.ts
-src/parser/*.interp
+src/parser/*
+!src/parser/.gitkeep

build.ts

@@ -0,0 +1,146 @@
+import { promises as fs } from 'fs';
+import rimraf from 'rimraf';
+import fetch from 'node-fetch';
+import path from 'path';
+import { exec } from 'child_process';
+import { once } from 'events';
+import { EOL } from 'os';
+import { promisify } from 'util';
+
+const files = [
+  'JavaParser.g4',
+  'JavaLexer.g4'
+];
+
+const main = async () => {
+  let isStale = await withLog(
+    'Checking if head is stale... ',
+    getIsStale(),
+    isStale => isStale ? 'Stale' : 'Up-to date'
+  )
+  if (!isStale && !process.argv.includes('--force')) {
+    console.log('Exiting, use --force to build anyway');
+    return;
+  }
+  let files = await withLog('Fetching files from upstream... ', getFiles());
+  await withLog('Writing files... ', writeFiles(files));
+  await withLog('Updating head.json... ', updateHead());
+  await withLog('Generating parser...\n', writeParser());
+  await withLog('Generating contexts... ', writeParserContexts());
+  await withLog('Compiling typescript files... ', writeJavascript());
+  console.log('Build successful!');
+}
+
+const getIsStale = async () => {
+  let [head, upstreamHead] = await Promise.all([getHead(), getUpstreamHead()]);
+  return files.some(file => head[file] !== upstreamHead[file]);
+}
+
+const getHead = async () =>
+  JSON.parse(
+    await fs.readFile(path.join(__dirname, 'src/head.json'), 'utf-8')
+  ) as { [file: string]: string };
+
+let upstreamHeadCache: { [file: string]: string } | undefined;
+const getUpstreamHead = async () => {
+  if (upstreamHeadCache) return upstreamHeadCache;
+
+  let upstreamHead = mergeAll(
+    await Promise.all(
+      files.map(async file => {
+        let res = await fetch(`https://api.github.com/repos/antlr/grammars-v4/commits?path=java/java/${file}`);
+        let commits = await res.json();
+        return { [file]: commits[0].sha as string };
+      })
+    )
+  )
+  upstreamHeadCache = upstreamHead;
+  return upstreamHead;
+}
+  
+const getFiles = async () =>
+  mergeAll(await Promise.all(
+    files.map(async file => {
+      let res = await fetch(`https://raw.githubusercontent.com/antlr/grammars-v4/master/java/java/${file}`)
+      let data = await res.text();
+      return { [file]: data };
+    })
+  ))
+
+const writeFiles = (files: { [file: string]: string }) =>
+  Promise.all(
+    Object.entries(files)
+    .map(([file, data]) =>
+      fs.writeFile(path.join(__dirname, 'src/parser/', file), data)
+    )
+  )
+
+const updateHead = async () =>
+  fs.writeFile(
+    path.join(__dirname, 'src/head.json'),
+    JSON.stringify(await getUpstreamHead(), null, '  ')
+  )
+
+const writeParser = () =>
+  execCommand(`${prependBinDir('antlr4ts')} -visitor -o src/parser -Xexact-output-dir src/parser/JavaLexer.g4 src/parser/JavaParser.g4`)
+
+const writeParserContexts = async () => {
+  let listenerSource = await fs.readFile(path.join(__dirname, '/src/parser/JavaParserListener.ts'), 'utf-8');
+
+  let exportList = 
+    listenerSource
+    .split(EOL)
+    .map((l) => {
+      let matches = l.match(/import\s*\{\s*(.*Context)\s*\}.*/);
+      if (matches === null) return null;
+      return matches[1];
+    })
+    .filter((c) => c !== null)
+    .reduce((list, context) => list + `  ${context},${EOL}`, '');
+
+  await fs.writeFile(
+    path.join(__dirname, '/src/parser/JavaContexts.ts'),
+    `export {${EOL}${exportList}} from './JavaParser';`
+  );
+}
+
+const writeJavascript = async () => {
+  await promisify(rimraf)(path.join(__dirname, "/dist"))
+  await execCommand(prependBinDir('tsc'))
+}
+
+const withLog = async <T>(
+  label: string,
+  promise: Promise<T>,
+  fulfilMessage: ((value: T) => string) = () => 'Done'
+) => {
+  process.stdout.write(label);
+  try {
+    let value = await promise;
+    process.stdout.write(fulfilMessage(value) + '\n')
+    return value;
+  } catch (error) {
+    process.stdout.write('Something went wrong\n');
+    throw error;
+  }
+}
+
+const execCommand = async (command: string) => {
+  let childProcess = exec(command, { cwd: __dirname })
+  childProcess.stdout.pipe(process.stdout);
+  childProcess.stderr.pipe(process.stderr);
+
+  let [code] = await once(childProcess, 'exit') as [number];
+  if (code !== 0) throw undefined;
+}
+
+const prependBinDir = (p: string) =>
+  path.join(__dirname, "/node_modules/.bin/", p);
+
+type MergeAll = <T extends object[]>(xs: T) => UnionToIntersection<T[number]>;
+const mergeAll: MergeAll = xs => xs.reduce((m, x) => ({ ...m, ...x }), {}) as any;
+  
+type UnionToIntersection<U> = 
+  (U extends any ? (k: U) => void : never) extends ((k: infer I) => void) ? I : never
+
+main();

generate-contexts.js

@@ -21,26 +21,28 @@
     "dist"
   ],
   "scripts": {
-    "build": "rimraf dist && npm run generate:parser && npm run generate:contexts && tsc",
-    "format": "prettier --write src/**.ts **/*.json",
+    "build": "ts-node build.ts",
+    "format": "prettier --write build.ts src/**.ts **/*.json",
     "prepublish": "yarn build",
-    "generate:parser": "antlr4ts -visitor -o src/parser -Xexact-output-dir src/parser/JavaLexer.g4 src/parser/JavaParser.g4",
-    "generate:contexts": "node generate-contexts.js",
     "precommit": "lint-staged",
     "postcommit": "git update-index --again",
     "test": "jest"
   },
   "devDependencies": {
     "@types/jest": "^26.0.4",
     "@types/node": "^14.0.22",
+    "@types/node-fetch": "^2.5.7",
+    "@types/rimraf": "^3.0.0",
     "antlr4ts-cli": "^0.5.0-alpha.3",
-    "husky": "^0.14.3",
+    "husky": "^4.2.5",
     "jest": "^26.1.0",
-    "lint-staged": "^7.2.0",
-    "prettier": "^1.13.7",
-    "rimraf": "^2.6.2",
+    "lint-staged": "^10.2.11",
+    "node-fetch": "^2.6.0",
+    "prettier": "^2.0.5",
+    "rimraf": "^3.0.2",
     "ts-jest": "^26.1.1",
-    "tslint": "^5.10.0",
+    "ts-node": "^8.10.2",
+    "tslint": "^6.1.2",
     "typescript": "^3.9.6"
   },
   "dependencies": {

package.json

@@ -0,0 +1,4 @@
+{
+  "JavaParser.g4": null,
+  "JavaLexer.g4": null
+}