add internal lock parser for extensibility and performance (#49)

Author: Simek

.eslintrc.json

@@ -15,7 +15,6 @@
     "sourceType": "module"
   },
   "rules": {
-    "indent": ["error", 2],
     "no-var": "error",
     "prefer-arrow-callback": "error",
     "prefer-const": "error",

dist/index.js

@@ -14,7 +14,6 @@
   "dependencies": {
     "@actions/core": "^1.6.0",
     "@actions/github": "^5.0.1",
-    "@yarnpkg/lockfile": "^1.1.0",
     "js-base64": "^3.7.2",
     "markdown-table": "^3.0.2",
     "semver": "^7.3.7"
@@ -23,6 +22,7 @@
     "@babel/core": "^7.17.9",
     "@babel/preset-env": "^7.16.11",
     "@vercel/ncc": "^0.33.4",
+    "@yarnpkg/lockfile": "^1.1.0",
     "babel-jest": "^27.5.1",
     "eslint": "^8.13.0",
     "eslint-config-prettier": "^8.5.0",

package.json

@@ -1,11 +1,10 @@
 const { debug, getBooleanInput, getInput, setFailed, warning } = require('@actions/core');
 const { context, getOctokit } = require('@actions/github');
-const lockfile = require('@yarnpkg/lockfile');
 const fs = require('fs');
 const { Base64 } = require('js-base64');
 const path = require('path');
 
-const { STATUS, countStatuses, diffLocks } = require('./utils');
+const { STATUS, countStatuses, diffLocks, parseLock } = require('./utils');
 const { createTable, createSummary } = require('./comment');
 
 const getCommentId = async (octokit, oktokitParams, issueNumber, commentHeader) => {
@@ -58,7 +57,7 @@ const run = async () => {
     }
 
     const content = fs.readFileSync(lockPath, { encoding: 'utf8' });
-    const updatedLock = lockfile.parse(content);
+    const updatedLock = parseLock(content);
 
     const oktokitParams = { owner, repo };
     debug('Oktokit params: ' + JSON.stringify(oktokitParams));
@@ -88,7 +87,7 @@ const run = async () => {
       throw Error('💥 Cannot fetch repository base lock file, aborting!');
     }
 
-    const baseLock = lockfile.parse(Base64.decode(baseLockData.data.content));
+    const baseLock = parseLock(Base64.decode(baseLockData.data.content));
     const lockChanges = diffLocks(baseLock, updatedLock);
     const lockChangesCount = Object.keys(lockChanges).length;
 

src/action.js

@@ -36,6 +36,67 @@ const formatLockEntry = obj =>
       })
   );
 
+export const parseLock = content => {
+  const lines = content.replaceAll('\r', '').replaceAll('"', '').split('\n');
+
+  if (!lines[1].includes('v1')) {
+    return {
+      type: 'error',
+      object: {}
+    };
+  }
+
+  const cleanedLines = lines.slice(4);
+  const maxIndex = cleanedLines.length - 1;
+
+  const entryChunks = [];
+  cleanedLines.reduce((previousValue, currentValue, currentIndex) => {
+    if (currentValue !== '' && currentIndex !== maxIndex) {
+      return [...previousValue, currentValue];
+    } else {
+      entryChunks.push([...previousValue, currentValue]);
+      return [];
+    }
+  }, []);
+
+  const result = entryChunks
+    .map(entryLines => {
+      const keys = entryLines[0].replaceAll(':', '').split(',');
+
+      const dependencies = entryLines[4]
+        ? Object.assign(
+            {},
+            ...entryLines.splice(5).map(dependencyLine => {
+              const parts = dependencyLine.trim().split(' ');
+              if (parts.length === 2) {
+                return {
+                  [parts[0]]: parts[1]
+                };
+              } else {
+                return {};
+              }
+            })
+          )
+        : undefined;
+
+      const entryObject = {
+        version: entryLines[1].split('version ')[1],
+        resolved: entryLines[2].split('resolved ')[1],
+        integrity: entryLines[3].split('integrity ')[1],
+        dependencies
+      };
+
+      return Object.assign({}, ...keys.map(key => ({ [key.trim()]: entryObject })));
+    })
+    .filter(Boolean);
+
+  // Retain the official parser result structure for a while
+  return {
+    type: 'success',
+    object: Object.assign({}, ...result)
+  };
+};
+
 export const diffLocks = (previous, current) => {
   const changes = {};
   const previousPackages = formatLockEntry(previous);

src/utils.js

@@ -0,0 +1,29 @@
+const lockfile = require('@yarnpkg/lockfile');
+
+const { getTestLockContent } = require('../testUtils');
+const { parseLock } = require('../../src/utils');
+
+test('naive performance test', () => {
+  const contentA = getTestLockContent('downgrade', 'a.lock');
+  const contentB = getTestLockContent('downgrade', 'b.lock');
+
+  console.time('@yarnpkg/lockfile');
+  const start = performance.now();
+
+  lockfile.parse(contentA);
+  lockfile.parse(contentB);
+
+  const end = performance.now();
+  console.timeEnd('@yarnpkg/lockfile');
+
+  console.time('Internal parser');
+  const internalStart = performance.now();
+
+  parseLock(contentA);
+  parseLock(contentB);
+
+  const internalEnd = performance.now();
+  console.timeEnd('Internal parser');
+
+  expect(end - start).toBeGreaterThan(internalEnd - internalStart);
+});

tests/performance/parse.test.js

@@ -0,0 +1,8 @@
+import fs from 'fs';
+import path from 'path';
+
+export const getTestLockContent = (testName, filename) => {
+  return fs.readFileSync(path.resolve(process.cwd(), './tests/unit/', testName, filename), {
+    encoding: 'utf8'
+  });
+};

tests/testUtils.js

@@ -1,24 +1,11 @@
-const lockfile = require('@yarnpkg/lockfile');
-const fs = require('fs');
-const path = require('path');
-
-const { diffLocks, STATUS, countStatuses } = require('../../src/utils');
-
-const getTestLockContent = (testName, filename) => {
-  const content = fs.readFileSync(
-    path.resolve(process.cwd(), './tests/unit/', testName, filename),
-    {
-      encoding: 'utf8'
-    }
-  );
-  return content;
-};
+const { diffLocks, STATUS, countStatuses, parseLock } = require('../../src/utils');
+const { getTestLockContent } = require('../testUtils');
 
 test('no downgrade detected', () => {
   const contentA = getTestLockContent('downgrade', 'a.lock');
   const contentB = getTestLockContent('downgrade', 'b.lock');
 
-  const result = diffLocks(lockfile.parse(contentA), lockfile.parse(contentB));
+  const result = diffLocks(parseLock(contentA), parseLock(contentB));
 
   expect(Object.keys(result).length).toBe(52);
 
@@ -32,7 +19,7 @@ test('no downgrade detected, multiple cases', () => {
   const contentA = getTestLockContent('downgrade-complex', 'a.lock');
   const contentB = getTestLockContent('downgrade-complex', 'b.lock');
 
-  const result = diffLocks(lockfile.parse(contentA), lockfile.parse(contentB));
+  const result = diffLocks(parseLock(contentA), parseLock(contentB));
 
   expect(Object.keys(result).length).toBe(389);