Bump minimum supported node version to 12

Author: Shubham Kanodia

src/cache.js

@@ -7,48 +7,62 @@
  * @see https://github.com/babel/babel-loader/issues/34
  * @see https://github.com/babel/babel-loader/pull/41
  */
+const fs = require("fs");
 const os = require("os");
+const path = require("path");
+const zlib = require("zlib");
 const crypto = require("crypto");
 const findCacheDir = require("find-cache-dir");
-const { open } = require("lmdb");
+const { promisify } = require("util");
 
 const transform = require("./transform");
 // Lazily instantiated when needed
 let defaultCacheDirectory = null;
-let cacheDB = null;
+
+const readFile = promisify(fs.readFile);
+const writeFile = promisify(fs.writeFile);
+const gunzip = promisify(zlib.gunzip);
+const gzip = promisify(zlib.gzip);
+const makeDir = require("make-dir");
 
 /**
- * Initialize cache
+ * Read the contents from the compressed file.
+ *
+ * @async
+ * @params {String} filename
+ * @params {Boolean} compress
  */
+const read = async function (filename, compress) {
+  const data = await readFile(filename + (compress ? ".gz" : ""));
+  const content = compress ? await gunzip(data) : data;
 
-async function initCacheDB(cacheDir, cacheCompression) {
-  if (cacheDB) return cacheDB;
-  const fallback = cacheDir !== os.tmpdir();
+  return JSON.parse(content.toString());
+};
 
-  try {
-    cacheDB = open({
-      path: cacheDir,
-      compression: cacheCompression,
-      sharedStructuresKey: Symbol.for(`structures`),
-    });
-  } catch (err) {
-    if (fallback) {
-      cacheDB = initCacheDB(os.tmpdir(), cacheCompression);
-    }
+/**
+ * Write contents into a compressed file.
+ *
+ * @async
+ * @params {String} filename
+ * @params {Boolean} compress
+ * @params {String} result
+ */
+const write = async function (filename, compress, result) {
+  const content = JSON.stringify(result);
 
-    throw err;
-  }
-}
+  const data = compress ? await gzip(content) : content;
+  return await writeFile(filename + (compress ? ".gz" : ""), data);
+};
 
 /**
- * Build the cache key for the cached file
+ * Build the filename for the cached file
  *
  * @params {String} source  File source code
  * @params {Object} options Options used
  *
  * @return {String}
  */
-const fileCacheKey = function (source, identifier, options) {
+const filename = function (source, identifier, options) {
   // md4 hashing is not supported starting with node v17.0.0
   const majorNodeVersion = parseInt(process.versions.node.split(".")[0], 10);
   let hashType = "md4";
@@ -62,7 +76,7 @@ const fileCacheKey = function (source, identifier, options) {
 
   hash.update(contents);
 
-  return hash.digest("hex");
+  return hash.digest("hex") + ".json";
 };
 
 /**
@@ -71,21 +85,51 @@ const fileCacheKey = function (source, identifier, options) {
  * @params {String} directory
  * @params {Object} params
  */
-const handleCache = async function (params) {
-  const { source, options = {}, cacheIdentifier } = params;
+const handleCache = async function (directory, params) {
+  const {
+    source,
+    options = {},
+    cacheIdentifier,
+    cacheDirectory,
+    cacheCompression,
+  } = params;
 
-  const cacheKey = fileCacheKey(source, cacheIdentifier, options);
+  const file = path.join(directory, filename(source, cacheIdentifier, options));
+
+  try {
+    // No errors mean that the file was previously cached
+    // we just need to return it
+    return await read(file, cacheCompression);
+  } catch (err) {}
 
-  // Fetch cached result if it exists
-  const cached = await cacheDB.get(cacheKey);
-  if (typeof cached !== "undefined") {
-    return cached;
+  const fallback =
+    typeof cacheDirectory !== "string" && directory !== os.tmpdir();
+
+  // Make sure the directory exists.
+  try {
+    await makeDir(directory);
+  } catch (err) {
+    if (fallback) {
+      return handleCache(os.tmpdir(), params);
+    }
+
+    throw err;
   }
 
-  // Otherwise, just transform the cacheKey
+  // Otherwise just transform the file
   // return it to the user asap and write it in cache
   const result = await transform(source, options);
-  cacheDB.put(cacheKey, result);
+
+  try {
+    await write(file, cacheCompression, result);
+  } catch (err) {
+    if (fallback) {
+      // Fallback to tmpdir if node_modules folder not writable
+      return handleCache(os.tmpdir(), params);
+    }
+
+    throw err;
+  }
 
   return result;
 };
@@ -129,7 +173,5 @@ module.exports = async function (params) {
     directory = defaultCacheDirectory;
   }
 
-  await initCacheDB(directory, params.cacheCompression);
-
-  return await handleCache(params);
+  return await handleCache(directory, params);
 };

test/cache.test.js

@@ -1,4 +1,5 @@
 import test from "ava";
+import fs from "fs";
 import path from "path";
 import rimraf from "rimraf";
 import webpack from "webpack";
@@ -11,7 +12,6 @@ const defaultCacheDir = path.join(
 const cacheDir = path.join(__dirname, "output/cache/cachefiles");
 const outputDir = path.join(__dirname, "output/cache");
 const babelLoader = path.join(__dirname, "../lib");
-const { open } = require("lmdb");
 
 const globalConfig = {
   mode: "development",
@@ -48,7 +48,7 @@ test.beforeEach.cb(t => rimraf(defaultCacheDir, t.end));
 test.afterEach.cb(t => rimraf(t.context.directory, t.end));
 test.afterEach.cb(t => rimraf(t.context.cacheDirectory, t.end));
 
-test.cb("should build a cache database in the cache directory", t => {
+test.cb("should output files to cache directory", t => {
   const config = Object.assign({}, globalConfig, {
     output: {
       path: t.context.directory,
@@ -73,14 +73,16 @@ test.cb("should build a cache database in the cache directory", t => {
     t.deepEqual(stats.compilation.errors, []);
     t.deepEqual(stats.compilation.warnings, []);
 
-    const cacheDB = open(t.context.cacheDirectory, { readOnly: true });
-    t.true(cacheDB.getStats().entryCount > 0);
-    t.end();
+    fs.readdir(t.context.cacheDirectory, (err, files) => {
+      t.is(err, null);
+      t.true(files.length > 0);
+      t.end();
+    });
   });
 });
 
-test.serial.cb.only(
-  "should add entries to cache db at standard cache dir by default",
+test.serial.cb(
+  "should output json.gz files to standard cache dir by default",
   t => {
     const config = Object.assign({}, globalConfig, {
       output: {
@@ -106,15 +108,56 @@ test.serial.cb.only(
       t.deepEqual(stats.compilation.errors, []);
       t.deepEqual(stats.compilation.warnings, []);
 
-      const cacheDB = open(defaultCacheDir, { readOnly: true });
-      t.true(cacheDB.getStats().entryCount > 0);
-      t.end();
+      fs.readdir(defaultCacheDir, (err, files) => {
+        files = files.filter(file => /\b[0-9a-f]{5,40}\.json\.gz\b/.test(file));
+
+        t.is(err, null);
+        t.true(files.length > 0);
+        t.end();
+      });
     });
   },
 );
 
 test.serial.cb(
-  "should add entries to cache db at standard cache dir if set to true in query",
+  "should output non-compressed files to standard cache dir when cacheCompression is set to false",
+  t => {
+    const config = Object.assign({}, globalConfig, {
+      output: {
+        path: t.context.directory,
+      },
+      module: {
+        rules: [
+          {
+            test: /\.jsx?/,
+            loader: babelLoader,
+            exclude: /node_modules/,
+            options: {
+              cacheDirectory: true,
+              cacheCompression: false,
+              presets: ["@babel/preset-env"],
+            },
+          },
+        ],
+      },
+    });
+
+    webpack(config, err => {
+      t.is(err, null);
+
+      fs.readdir(defaultCacheDir, (err, files) => {
+        files = files.filter(file => /\b[0-9a-f]{5,40}\b/.test(file));
+
+        t.is(err, null);
+        t.true(files.length > 0);
+        t.end();
+      });
+    });
+  },
+);
+
+test.serial.cb(
+  "should output files to standard cache dir if set to true in query",
   t => {
     const config = Object.assign({}, globalConfig, {
       output: {
@@ -136,9 +179,14 @@ test.serial.cb(
       t.deepEqual(stats.compilation.errors, []);
       t.deepEqual(stats.compilation.warnings, []);
 
-      const cacheDB = open(t.context.cacheDirectory, { readOnly: true });
-      t.true(cacheDB.getStats().entryCount > 0);
-      t.end();
+      fs.readdir(defaultCacheDir, (err, files) => {
+        files = files.filter(file => /\b[0-9a-f]{5,40}\.json\.gz\b/.test(file));
+
+        t.is(err, null);
+
+        t.true(files.length > 0);
+        t.end();
+      });
     });
   },
 );
@@ -172,14 +220,16 @@ test.cb("should read from cache directory if cached file exists", t => {
 
     webpack(config, err => {
       t.is(err, null);
-      const cacheDB = open(t.context.cacheDirectory, { readOnly: true });
-      t.true(cacheDB.getStats().entryCount > 0);
-      t.end();
+      fs.readdir(t.context.cacheDirectory, (err, files) => {
+        t.is(err, null);
+        t.true(files.length > 0);
+        t.end();
+      });
     });
   });
 });
 
-test.cb("should have one cache entry per module", t => {
+test.cb("should have one file per module", t => {
   const config = Object.assign({}, globalConfig, {
     output: {
       path: t.context.directory,
@@ -204,13 +254,15 @@ test.cb("should have one cache entry per module", t => {
     t.deepEqual(stats.compilation.errors, []);
     t.deepEqual(stats.compilation.warnings, []);
 
-    const cacheDB = open(t.context.cacheDirectory, { readOnly: true });
-    t.true(cacheDB.getStats().entryCount === 3);
-    t.end();
+    fs.readdir(t.context.cacheDirectory, (err, files) => {
+      t.is(err, null);
+      t.true(files.length === 3);
+      t.end();
+    });
   });
 });
 
-test.cb("should add a new cache entry if the identifier changes", t => {
+test.cb("should generate a new file if the identifier changes", t => {
   const configs = [
     Object.assign({}, globalConfig, {
       output: {
@@ -261,9 +313,11 @@ test.cb("should add a new cache entry if the identifier changes", t => {
       counter -= 1;
 
       if (!counter) {
-        const cacheDB = open(t.context.cacheDirectory, { readOnly: true });
-        t.true(cacheDB.getStats().entryCount === 6);
-        t.end();
+        fs.readdir(t.context.cacheDirectory, (err, files) => {
+          t.is(err, null);
+          t.true(files.length === 6);
+          t.end();
+        });
       }
     });
   });
@@ -320,8 +374,10 @@ test.cb("should allow to specify the .babelrc file", t => {
     t.deepEqual(multiStats.stats[1].compilation.errors, []);
     t.deepEqual(multiStats.stats[1].compilation.warnings, []);
 
-    const cacheDB = open(t.context.cacheDirectory, { readOnly: true });
-    t.true(cacheDB.getStats().entryCount === 1);
-    t.end();
+    fs.readdir(t.context.cacheDirectory, (err, files) => {
+      t.is(err, null);
+      t.true(files.length === 2);
+      t.end();
+    });
   });
 });