polish: use our own config serializer

babel · Jul 11, 2024 · 698265a · 698265a
1 parent 2237bd6
commit 698265a
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Showing 5 changed files with 88 additions and 12 deletions.
diff --git a/package.json b/package.json
@@ -10,7 +10,6 @@
     "node": ">= 14.15.0"
   },
   "dependencies": {
-    "fast-stable-stringify": "^1.0.0",
     "find-cache-dir": "^4.0.0",
     "schema-utils": "^4.0.0"
   },

diff --git a/src/cache.js b/src/cache.js
@@ -13,10 +13,11 @@ const zlib = require("zlib");
 const crypto = require("crypto");
 const { promisify } = require("util");
 const { readFile, writeFile, mkdir } = require("fs/promises");
+// Lazily instantiated when needed
 const findCacheDirP = import("find-cache-dir");
 
 const transform = require("./transform");
-// Lazily instantiated when needed
+const serialize = require("./serialize");
 let defaultCacheDirectory = null;
 
 let hashType = "sha256";
@@ -29,7 +30,6 @@ try {
 
 const gunzip = promisify(zlib.gunzip);
 const gzip = promisify(zlib.gzip);
-const stringify = require("fast-stable-stringify");
 
 /**
  * Read the contents from the compressed file.
@@ -71,7 +71,7 @@ const write = async function (filename, compress, result) {
 const filename = function (source, identifier, options) {
   const hash = crypto.createHash(hashType);
 
-  hash.update(stringify({ source, options, identifier }));
+  hash.update(serialize([options, source, identifier]));
 
   return hash.digest("hex") + ".json";
 };

diff --git a/src/serialize.js b/src/serialize.js
@@ -0,0 +1,83 @@
+var objToString = Object.prototype.toString;
+var objKeys = Object.getOwnPropertyNames;
+
+/**
+ * A custom Babel options serializer
+ *
+ * Intentional deviation from JSON.stringify:
+ * 1. Object properties are sorted before seralizing
+ * 2. The output is NOT a valid JSON: e.g.
+ *    The output does not enquote strings, which means a JSON-like string '{"a":1}'
+ *    will share the same result with an JS object { a: 1 }. This is not an issue
+ *    for Babel options, but it can not be used for general serialization purpose
+ * 3. Only 20% slower than the native JSON.stringify on V8
+ *
+ * This function is a fork from https://github.com/nickyout/fast-stable-stringify
+ * @param {*} val Babel options
+ * @param {*} isArrayProp
+ * @returns serialized Babel options
+ */
+function serialize(val, isArrayProp) {
+  var i, max, str, keys, key, propVal, toStr;
+  if (val === true) {
+    return "!0";
+  }
+  if (val === false) {
+    return "!1";
+  }
+  switch (typeof val) {
+    case "object":
+      if (val === null) {
+        return null;
+      } else if (val.toJSON && typeof val.toJSON === "function") {
+        return serialize(val.toJSON(), isArrayProp);
+      } else {
+        toStr = objToString.call(val);
+        if (toStr === "[object Array]") {
+          str = "[";
+          max = val.length - 1;
+          for (i = 0; i < max; i++) {
+            str += serialize(val[i], true) + ",";
+          }
+          if (max > -1) {
+            str += serialize(val[i], true);
+          }
+          return str + "]";
+        } else if (toStr === "[object Object]") {
+          // only object is left
+          keys = objKeys(val).sort();
+          max = keys.length;
+          str = "{";
+          i = 0;
+          while (i < max) {
+            key = keys[i];
+            propVal = serialize(val[key], false);
+            if (propVal !== undefined) {
+              if (str) {
+                str += ",";
+              }
+              str += '"' + key + '":' + propVal;
+            }
+            i++;
+          }
+          return str + "}";
+        } else {
+          return JSON.stringify(val);
+        }
+      }
+    case "function":
+    case "undefined":
+      return isArrayProp ? null : undefined;
+    case "string":
+      return val;
+    default:
+      return isFinite(val) ? val : null;
+  }
+}
+
+module.exports = function (val) {
+  var returnVal = serialize(val, false);
+  if (returnVal !== undefined) {
+    return "" + returnVal;
+  }
+};
diff --git a/test/cache.test.js b/test/cache.test.js
@@ -323,5 +323,7 @@ test("should allow to specify the .babelrc file", async t => {
   t.deepEqual(multiStats.stats[1].compilation.warnings, []);
 
   const files = fs.readdirSync(t.context.cacheDirectory);
+  // The two configs resolved to same Babel config because "fixtures/babelrc"
+  // is { "presets": ["@babel/preset-env"] }
   t.true(files.length === 1);
 });
diff --git a/yarn.lock b/yarn.lock
@@ -2283,7 +2283,6 @@ __metadata:
     eslint: ^9.6.0
     eslint-config-prettier: ^9.1.0
     eslint-plugin-prettier: ^5.1.3
-    fast-stable-stringify: ^1.0.0
     find-cache-dir: ^4.0.0
     globals: ^15.8.0
     husky: ^8.0.3
@@ -3556,13 +3555,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"fast-stable-stringify@npm:^1.0.0":
-  version: 1.0.0
-  resolution: "fast-stable-stringify@npm:1.0.0"
-  checksum: ef1203d246a7e8ac15e2bfbda0a89fa375947bccf9f7910be0ea759856dbe8ea5024a0d8cc2cceabe18a9cb67e95927b78bb6173a3ae37ec55a518cf36e5244b
-  languageName: node
-  linkType: hard
-
 "fastq@npm:^1.6.0":
   version: 1.17.1
   resolution: "fastq@npm:1.17.1"