feat(std/node): support hex/base64 encoding in fs.readFile/fs.writeFile (#6512)

std/node/_fs/_fs_common.ts

@@ -61,7 +61,11 @@ export function getEncoding(
 
 export function checkEncoding(encoding: Encodings | null): Encodings | null {
   if (!encoding) return null;
-  if (encoding === "utf8" || encoding === "utf-8") {
+
+  encoding = encoding.toLowerCase() as Encodings;
+  if (["utf8", "hex", "base64"].includes(encoding)) return encoding;
+
+  if (encoding === "utf-8") {
     return "utf8";
   }
   if (encoding === "binary") {
@@ -70,16 +74,9 @@ export function checkEncoding(encoding: Encodings | null): Encodings | null {
     // node -e "require('fs').readFile('../world.txt', 'buffer', console.log)"
   }
 
-  const notImplementedEncodings = [
-    "utf16le",
-    "latin1",
-    "base64",
-    "hex",
-    "ascii",
-    "ucs2",
-  ];
+  const notImplementedEncodings = ["utf16le", "latin1", "ascii", "ucs2"];
 
-  if (notImplementedEncodings.includes(encoding)) {
+  if (notImplementedEncodings.includes(encoding as string)) {
     notImplemented(`"${encoding}" encoding`);
   }
 

std/node/_fs/_fs_readFile_test.ts

@@ -29,11 +29,37 @@ Deno.test("readFileEncodeUtf8Success", async function () {
       res(data);
     });
   });
-
   assertEquals(typeof data, "string");
   assertEquals(data as string, "hello world");
 });
 
+Deno.test("readFileEncodeHexSuccess", async function () {
+  const data = await new Promise((res, rej) => {
+    readFile(testData, { encoding: "hex" }, (err, data) => {
+      if (err) {
+        rej(err);
+      }
+      res(data);
+    });
+  });
+
+  assertEquals(typeof data, "string");
+  assertEquals(data as string, "68656c6c6f20776f726c64");
+});
+
+Deno.test("readFileEncodeBase64Success", async function () {
+  const data = await new Promise((res, rej) => {
+    readFile(testData, { encoding: "base64" }, (err, data) => {
+      if (err) {
+        rej(err);
+      }
+      res(data);
+    });
+  });
+  assertEquals(typeof data, "string");
+  assertEquals(data as string, "aGVsbG8gd29ybGQ=");
+});
+
 Deno.test("readFileEncodingAsString", async function () {
   const data = await new Promise((res, rej) => {
     readFile(testData, "utf8", (err, data) => {
@@ -60,6 +86,18 @@ Deno.test("readFileEncodeUtf8Success", function () {
   assertEquals(data as string, "hello world");
 });
 
+Deno.test("readFileEncodeHexSuccess", function () {
+  const data = readFileSync(testData, { encoding: "hex" });
+  assertEquals(typeof data, "string");
+  assertEquals(data as string, "68656c6c6f20776f726c64");
+});
+
+Deno.test("readFileEncodeBase64Success", function () {
+  const data = readFileSync(testData, { encoding: "base64" });
+  assertEquals(typeof data, "string");
+  assertEquals(data as string, "aGVsbG8gd29ybGQ=");
+});
+
 Deno.test("readFileEncodeAsString", function () {
   const data = readFileSync(testData, "utf8");
   assertEquals(typeof data, "string");

std/node/_fs/_fs_writeFile.ts

@@ -1,6 +1,7 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 import { notImplemented } from "../_utils.ts";
 import { fromFileUrl } from "../path.ts";
+import { Buffer } from "../buffer.ts";
 
 import {
   Encodings,
@@ -40,8 +41,7 @@ export function writeFile(
   const encoding = checkEncoding(getEncoding(options)) || "utf8";
   const openOptions = getOpenOptions(flag || "w");
 
-  if (typeof data === "string" && encoding === "utf8")
-    data = new TextEncoder().encode(data) as Uint8Array;
+  if (typeof data === "string") data = Buffer.from(data, encoding);
 
   const isRid = typeof pathOrRid === "number";
   let file;
@@ -87,8 +87,7 @@ export function writeFileSync(
   const encoding = checkEncoding(getEncoding(options)) || "utf8";
   const openOptions = getOpenOptions(flag || "w");
 
-  if (typeof data === "string" && encoding === "utf8")
-    data = new TextEncoder().encode(data) as Uint8Array;
+  if (typeof data === "string") data = Buffer.from(data, encoding);
 
   const isRid = typeof pathOrRid === "number";
   let file;

std/node/_fs/_fs_writeFile_test.ts

@@ -6,6 +6,7 @@ import {
   assertThrows,
 } from "../../testing/asserts.ts";
 import { writeFile, writeFileSync } from "./_fs_writeFile.ts";
+import { TextEncodings } from "./_fs_common.ts";
 import * as path from "../../path/mod.ts";
 
 const testDataDir = path.resolve(path.join("node", "_fs", "testdata"));
@@ -73,43 +74,18 @@ Deno.test(
   function testUnsupportedEncoding() {
     assertThrows(
       () => {
-        writeFile("some/path", "some data", "hex", () => {});
+        writeFile("some/path", "some data", "utf16le", () => {});
       },
       Error,
-      `Not implemented: "hex" encoding`
+      `Not implemented: "utf16le" encoding`
     );
 
     assertThrows(
       () => {
-        writeFileSync("some/path", "some data", "hex");
+        writeFileSync("some/path", "some data", "utf16le");
       },
       Error,
-      `Not implemented: "hex" encoding`
-    );
-
-    assertThrows(
-      () => {
-        writeFile(
-          "some/path",
-          "some data",
-          {
-            encoding: "base64",
-          },
-          () => {}
-        );
-      },
-      Error,
-      `Not implemented: "base64" encoding`
-    );
-
-    assertThrows(
-      () => {
-        writeFileSync("some/path", "some data", {
-          encoding: "base64",
-        });
-      },
-      Error,
-      `Not implemented: "base64" encoding`
+      `Not implemented: "utf16le" encoding`
     );
   }
 );
@@ -152,6 +128,36 @@ Deno.test(
   }
 );
 
+Deno.test(
+  "Data is written to correct file encodings",
+  async function testCorrectWriteUsingDifferentEncodings() {
+    const encodings = [
+      ["hex", "68656c6c6f20776f726c64"],
+      ["HEX", "68656c6c6f20776f726c64"],
+      ["base64", "aGVsbG8gd29ybGQ="],
+      ["BASE64", "aGVsbG8gd29ybGQ="],
+      ["utf8", "hello world"],
+      ["utf-8", "hello world"],
+    ];
+
+    for (const [encoding, value] of encodings) {
+      const res = await new Promise((resolve) => {
+        writeFile(
+          "_fs_writeFile_test_file.txt",
+          value,
+          encoding as TextEncodings,
+          resolve
+        );
+      });
+
+      const data = await Deno.readFile("_fs_writeFile_test_file.txt");
+      await Deno.remove("_fs_writeFile_test_file.txt");
+      assertEquals(res, null);
+      assertEquals(decoder.decode(data), "hello world");
+    }
+  }
+);
+
 Deno.test("Path can be an URL", async function testCorrectWriteUsingURL() {
   const url = new URL(
     Deno.build.os === "windows"
@@ -234,6 +240,29 @@ Deno.test(
   }
 );
 
+Deno.test(
+  "Data is written to correct file encodings",
+  function testCorrectWriteSyncUsingDifferentEncodings() {
+    const encodings = [
+      ["hex", "68656c6c6f20776f726c64"],
+      ["HEX", "68656c6c6f20776f726c64"],
+      ["base64", "aGVsbG8gd29ybGQ="],
+      ["BASE64", "aGVsbG8gd29ybGQ="],
+      ["utf8", "hello world"],
+      ["utf-8", "hello world"],
+    ];
+
+    for (const [encoding, value] of encodings) {
+      const file = "_fs_writeFileSync_test_file";
+      writeFileSync(file, value, encoding as TextEncodings);
+
+      const data = Deno.readFileSync(file);
+      Deno.removeSync(file);
+      assertEquals(decoder.decode(data), "hello world");
+    }
+  }
+);
+
 Deno.test(
   "Data is written synchronously to correct file",
   function testCorrectWriteSyncUsingPath() {

std/node/_fs/promises/_fs_readFile_test.ts

@@ -34,6 +34,18 @@ Deno.test("readFileStringObjectSuccess", async function () {
   assertEquals(data, "hello world");
 });
 
+Deno.test("readFileEncodeHexSuccess", async function () {
+  const data: string = await readFile(testData, { encoding: "hex" });
+  assertEquals(typeof data, "string");
+  assertEquals(data as string, "68656c6c6f20776f726c64");
+});
+
+Deno.test("readFileEncodeBase64Success", async function () {
+  const data: string = await readFile(testData, { encoding: "base64" });
+  assertEquals(typeof data, "string");
+  assertEquals(data as string, "aGVsbG8gd29ybGQ=");
+});
+
 Deno.test("readFileStringSuccess", async function () {
   const data: string = await readFile(testData, "utf8");
 

std/node/_fs/promises/_fs_writeFile_test.ts

@@ -6,6 +6,7 @@ import {
   assertThrowsAsync,
 } from "../../../testing/asserts.ts";
 import { writeFile } from "./_fs_writeFile.ts";
+import { TextEncodings } from "../_fs_common.ts";
 
 const decoder = new TextDecoder("utf-8");
 
@@ -35,19 +36,10 @@ Deno.test(
   function testUnsupportedEncoding() {
     assertThrowsAsync(
       async () => {
-        await writeFile("some/path", "some data", "hex");
+        await writeFile("some/path", "some data", "utf16le");
       },
       Error,
-      `Not implemented: "hex" encoding`
-    );
-    assertThrowsAsync(
-      async () => {
-        await writeFile("some/path", "some data", {
-          encoding: "base64",
-        });
-      },
-      Error,
-      `Not implemented: "base64" encoding`
+      `Not implemented: "utf16le" encoding`
     );
   }
 );
@@ -85,6 +77,32 @@ Deno.test(
   }
 );
 
+Deno.test(
+  "Data is written to correct file encodings",
+  async function testCorrectWritePromiseUsingDifferentEncodings() {
+    const encodings = [
+      ["hex", "68656c6c6f20776f726c64"],
+      ["HEX", "68656c6c6f20776f726c64"],
+      ["base64", "aGVsbG8gd29ybGQ="],
+      ["BASE64", "aGVsbG8gd29ybGQ="],
+      ["utf8", "hello world"],
+      ["utf-8", "hello world"],
+    ];
+
+    for (const [encoding, value] of encodings) {
+      await writeFile(
+        "_fs_writeFile_test_file.txt",
+        value,
+        encoding as TextEncodings
+      );
+
+      const data = await Deno.readFile("_fs_writeFile_test_file.txt");
+      await Deno.remove("_fs_writeFile_test_file.txt");
+      assertEquals(decoder.decode(data), "hello world");
+    }
+  }
+);
+
 Deno.test("Mode is correctly set", async function testCorrectFileMode() {
   if (Deno.build.os === "windows") return;
   const filename = "_fs_writeFile_test_file.txt";