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products/Sources/formale Sprachen/C/Firefox/xpcom/ioutils/tests/ (Firefox Browser Version 153.0.1^©) Datei vom 27.6.2026 mit Größe 15 kB

Quelle test_ioutils_read_write_utf8.html

Sprache: HTML

products/Sources/formale Sprachen/C/Firefox/xpcom/ioutils/tests/test_ioutils_read_write_utf8.html

<!DOCTYPE HTML>
<html>

<head>
  <meta charset="utf-8">
  <title>Test the IOUtils file I/O API</title>
  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
  <link rel="stylesheet" href="chrome://mochikit/content/tests/SimpleTest/test.css" />
  <script src="file_ioutils_test_fixtures.js"></script>
  <script>
    "use strict";

    const { Assert } = ChromeUtils.importESModule(
      "resource://testing-common/Assert.sys.mjs"
    );

    // This is an impossible sequence of bytes in an UTF-8 encoded file.
    // See section 3.5.3 of this text:
    // https://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-test.txt
    const invalidUTF8 = Uint8Array.of(0xfe, 0xfe, 0xff, 0xff);

    add_task(async function test_read_utf8_failure() {
      info("Test attempt to read non-existent file (UTF8)");
      const doesNotExist = PathUtils.join(PathUtils.tempDir, "does_not_exist.tmp");
      await Assert.rejects(
        IOUtils.readUTF8(doesNotExist),
        /NotFoundError: Could not open `.*'/,
        "IOUtils::readUTF8 rejects when file does not exist"
      );

      info("Test attempt to read invalid UTF-8");
      const invalidUTF8File = PathUtils.join(PathUtils.tempDir, "invalid_utf8.tmp");

      // Deliberately write the invalid byte sequence to file.
      await IOUtils.write(invalidUTF8File, invalidUTF8);

      await Assert.rejects(
        IOUtils.readUTF8(invalidUTF8File),
        /NotReadableError: Could not read `.*': file is not UTF-8 encoded/,
        "IOUtils::readUTF8 will reject when reading a file that is not valid UTF-8"
      );

      await cleanup(invalidUTF8File);
    });

    add_task(async function test_write_utf8_no_overwrite() {
      // Make a new file, and try to write to it with overwrites disabled.
      const tmpFileName = PathUtils.join(PathUtils.tempDir, "test_ioutils_write_utf8_overwrite.tmp");
      const untouchableContents = "Can't touch this!\n";
      await IOUtils.writeUTF8(tmpFileName, untouchableContents);

      const newContents = "Nah nah nah!\n";
      await Assert.rejects(
        IOUtils.writeUTF8(tmpFileName, newContents, {
          mode: "create",
        }),
        /NoModificationAllowedError: Could not write to `.*': refusing to overwrite file, `mode' is not "overwrite"/,
        "IOUtils::writeUTF8 rejects writing to existing file if overwrites are disabled"
      );
      ok(
        await fileHasTextContents(tmpFileName, untouchableContents),
        "IOUtils::writeUTF8 doesn't change target file when overwrite is refused"
      );

      const bytesWritten = await IOUtils.writeUTF8(
        tmpFileName,
        newContents,
        { mode: "overwrite" }
      );
      is(
        bytesWritten,
        newContents.length,
        "IOUtils::writeUTF8 can overwrite files if specified"
      );
      ok(
        await fileHasTextContents(tmpFileName, newContents),
        "IOUtils::writeUTF8 overwrites with the expected contents"
      );

      await cleanup(tmpFileName);
    });

    add_task(async function test_write_with_backup() {
      info("Test backup file option with non-existing file");
      let fileContents = "Original file contents";
      let destFileName = PathUtils.join(PathUtils.tempDir, "test_write_utf8_with_backup_option.tmp");
      let backupFileName = destFileName + ".backup";
      let bytesWritten =
        await IOUtils.writeUTF8(destFileName, fileContents, {
          backupFile: backupFileName,
        });
      ok(
        await fileHasTextContents(destFileName, "Original file contents"),
        "IOUtils::writeUTF8 creates a new file with the correct contents"
      );
      ok(
        !await fileExists(backupFileName),
        "IOUtils::writeUTF8 does not create a backup if the target file does not exist"
      );
      is(
        bytesWritten,
        fileContents.length,
        "IOUtils::write correctly writes to a new file without performing a backup"
      );

      info("Test backup file option with existing destination");
      let newFileContents = "New file contents";
      ok(await fileExists(destFileName), `Expected ${destFileName} to exist`);
      bytesWritten =
        await IOUtils.writeUTF8(destFileName, newFileContents, {
          backupFile: backupFileName,
        });
      ok(
        await fileHasTextContents(backupFileName, "Original file contents"),
        "IOUtils::writeUTF8 can backup an existing file before writing"
      );
      ok(
        await fileHasTextContents(destFileName, "New file contents"),
        "IOUtils::writeUTF8 can create the target with the correct contents"
      );
      is(
        bytesWritten,
        newFileContents.length,
        "IOUtils::writeUTF8 correctly writes to the target after taking a backup"
      );

      await cleanup(destFileName, backupFileName);
    });

    add_task(async function test_write_with_backup_and_tmp() {
      info("Test backup with tmp and backup file options, non-existing destination");
      let fileContents = "Original file contents";
      let destFileName = PathUtils.join(PathUtils.tempDir, "test_write_utf8_with_backup_and_tmp_options.tmp");
      let backupFileName = destFileName + ".backup";
      let tmpFileName = PathUtils.join(PathUtils.tempDir, "temp_file.tmp");
      let bytesWritten =
        await IOUtils.writeUTF8(destFileName, fileContents, {
          backupFile: backupFileName,
          tmpPath: tmpFileName,
        });
      ok(!await fileExists(tmpFileName), "IOUtils::writeUTF8 cleans up the tmpFile");
      ok(
        !await fileExists(backupFileName),
        "IOUtils::writeUTF8 does not create a backup if the target file does not exist"
      );
      ok(
        await fileHasTextContents(destFileName, "Original file contents"),
        "IOUtils::writeUTF8 can write to the destination when a temporary file is used"
      );
      is(
        bytesWritten,
        fileContents.length,
        "IOUtils::writeUTF8 can copy tmp file to destination without performing a backup"
      );

      info("Test backup with tmp and backup file options, existing destination");
      let newFileContents = "New file contents";
      bytesWritten =
        await IOUtils.writeUTF8(destFileName, newFileContents, {
          backupFile: backupFileName,
          tmpPath: tmpFileName,
        });

      ok(!await fileExists(tmpFileName), "IOUtils::writeUTF8 cleans up the tmpFile");
      ok(
        await fileHasTextContents(backupFileName, "Original file contents"),
        "IOUtils::writeUTF8 can create a backup if the target file exists"
      );
      ok(
        await fileHasTextContents(destFileName, "New file contents"),
        "IOUtils::writeUTF8 can write to the destination when a temporary file is used"
      );
      is(
        bytesWritten,
        newFileContents.length,
        "IOUtils::writeUTF8 can move tmp file to destination after performing a backup"
      );

      await cleanup(destFileName, backupFileName);
    });

    add_task(async function test_empty_read_and_write_utf8() {
      const tmpFileName = PathUtils.join(PathUtils.tempDir, "test_ioutils_empty_utf8.tmp");
      const emptyString = ""
      const bytesWritten = await IOUtils.writeUTF8(
        tmpFileName,
        emptyString
      );
      is(bytesWritten, 0, "IOUtils::writeUTF8 can create an empty file");

      const nothing = await IOUtils.readUTF8(tmpFileName);
      is(nothing.length, 0, "IOUtils::readUTF8 can read empty files");

      await cleanup(tmpFileName);
    });

    add_task(async function test_full_read_and_write_utf8() {
      // Write a file.
      info("Test writing emoji file");
      const tmpFileName = PathUtils.join(PathUtils.tempDir, "test_ioutils_emoji.tmp");

      // Make sure non-ASCII text is supported for writing and reading back.
      // For fun, a sampling of space-separated emoji characters from different
      // Unicode versions, including multi-byte glyphs that are rendered using
      // ZWJ sequences.
      const emoji = "☕️ ⚧️ �� ️‍�� ‍☠️ ��";
      const expectedBytes = 71;
      const bytesWritten = await IOUtils.writeUTF8(tmpFileName, emoji);
      is(
        bytesWritten,
        expectedBytes,
        "IOUtils::writeUTF8 can write emoji to file"
      );

      // Read it back.
      info("Test reading emoji from file");
      let fileContents = await IOUtils.readUTF8(tmpFileName);
      ok(
        emoji == fileContents &&
        emoji.length == fileContents.length,
        "IOUtils::readUTF8 can read back entire file"
      );

      // Clean up.
      await cleanup(tmpFileName);
    });

    add_task(async function test_write_utf8_relative_path() {
      const tmpFileName = "test_ioutils_write_utf8_relative_path.tmp";

      info("Test writing a file at a relative destination");
      await Assert.rejects(
        IOUtils.writeUTF8(tmpFileName, "foo"),
        /OperationError: Could not write to `.*': could not parse path $NS_ERROR_FILE_UNRECOGNIZED_PATH$/,
        "IOUtils::writeUTF8 only works with absolute paths"
      );
    });

    add_task(async function test_read_utf8_relative_path() {
      const tmpFileName = "test_ioutils_read_utf8_relative_path.tmp";

      info("Test reading a file at a relative destination");
      await Assert.rejects(
        IOUtils.readUTF8(tmpFileName),
        /OperationError: Could not read `.*': could not parse path $NS_ERROR_FILE_UNRECOGNIZED_PATH$/,
        "IOUtils::readUTF8 only works with absolute paths"
      );
    });

    add_task(async function test_utf8_lz4() {
      const tmpFileName = PathUtils.join(PathUtils.tempDir, "test_ioutils_utf8_lz4.tmp");

      info("Test writing lz4 encoded UTF-8 string");
      const emoji = "☕️ ⚧️ �� ️‍�� ‍☠️ ��";
      let bytesWritten = await IOUtils.writeUTF8(tmpFileName, emoji, { compress: true });
      is(bytesWritten, 83, "Expected to write 64 bytes");

      info("Test reading lz4 encoded UTF-8 string");
      let readData = await IOUtils.readUTF8(tmpFileName, { decompress: true });
      is(readData, emoji, "IOUtils can write and read back UTF-8 LZ4 encoded data");

      info("Test writing lz4 compressed UTF-8 string");
      const lotsOfCoffee = new Array(24).fill("☕️").join(""); // ☕️ is 3 bytes in UTF-8: \0xe2 \0x98 \0x95
      bytesWritten = await IOUtils.writeUTF8(tmpFileName, lotsOfCoffee, { compress: true });
      console.log(bytesWritten);
      is(bytesWritten, 28, "Expected 72 bytes to compress to 28 bytes");

      info("Test reading lz4 encoded UTF-8 string");
      readData = await IOUtils.readUTF8(tmpFileName, { decompress: true });
      is(readData, lotsOfCoffee, "IOUtils can write and read back UTF-8 LZ4 compressed data");

      info("Test writing empty lz4 compressed UTF-8 string")
      const empty = "";
      bytesWritten = await IOUtils.writeUTF8(tmpFileName, empty, { compress: true });
      is(bytesWritten, 12, "Expected to write just the LZ4 header");

      info("Test reading empty lz4 compressed UTF-8 string")
      const readEmpty = await IOUtils.readUTF8(tmpFileName, { decompress: true });
      is(readEmpty, empty, "IOUtils can write and read back empty buffers with LZ4");
      const readEmptyRaw = await IOUtils.readUTF8(tmpFileName, { decompress: false });
      is(readEmptyRaw.length, 12, "Expected to read back just the LZ4 header");

      await cleanup(tmpFileName);
    });

    add_task(async function test_utf8_lz4_bad_call() {
      const tmpFileName = PathUtils.join(PathUtils.tempDir, "test_ioutils_utf8_lz4_bad_call.tmp");

      info("readUTF8 ignores the maxBytes option if provided");
      const emoji = "☕️ ⚧️ �� ️‍�� ‍☠️ ��";
      let bytesWritten = await IOUtils.writeUTF8(tmpFileName, emoji, { compress: true });
      is(bytesWritten, 83, "Expected to write 83 bytes");

      let readData = await IOUtils.readUTF8(tmpFileName, { maxBytes: 4, decompress: true });
      is(readData, emoji, "IOUtils can write and read back UTF-8 LZ4 encoded data");

      await cleanup(tmpFileName)
    });

    add_task(async function test_utf8_lz4_failure() {
      const tmpFileName = PathUtils.join(PathUtils.tempDir, "test_ioutils_utf8_lz4_fail.tmp");

      info("Test decompression of non-lz4 UTF-8 string");
      const repeatedBytes = Uint8Array.of(...new Array(50).fill(1));
      await IOUtils.write(tmpFileName, repeatedBytes, { compress: false });

      await Assert.rejects(
        IOUtils.readUTF8(tmpFileName, { decompress: true }),
        /NotReadableError: Could not read `.*': could not decompress file: invalid LZ4 header: wrong magic number: `01 01 01 01 01 01 01 01 01 01 01 01' $NS_ERROR_FILE_CORRUPTED$/,
        "IOUtils::readUTF8 fails to decompress LZ4 data with a bad header"
      );

      info("Test UTF-8 decompression of short byte buffer");
      const elevenBytes = Uint8Array.of(...new Array(11).fill(1));
      await IOUtils.write(tmpFileName, elevenBytes, { compress: false });

      await Assert.rejects(
        IOUtils.readUTF8(tmpFileName, { decompress: true }),
        /NotReadableError: Could not read `.*': could not decompress file: buffer is too small $NS_ERROR_FILE_CORRUPTED$/,
        "IOUtils::readUTF8 fails to decompress LZ4 data with missing header"
      );

      info("Test UTF-8 decompression of valid header, but corrupt contents");
      const headerFor10bytes = [109, 111, 122, 76, 122, 52, 48, 0, 10, 0, 0, 0] // "mozlz40\0" + 4 byte length
      const badContents = new Array(11).fill(255); // Bad leading byte, followed by uncompressed stream.
      const goodHeaderBadContents = Uint8Array.of(...headerFor10bytes, ...badContents);
      await IOUtils.write(tmpFileName, goodHeaderBadContents, { compress: false });

      await Assert.rejects(
        IOUtils.readUTF8(tmpFileName, { decompress: true }),
        /NotReadableError: Could not read `.*': could not decompress file: the file may be corrupt $NS_ERROR_FILE_CORRUPTED$/,
        "IOUtils::readUTF8 fails to read corrupt LZ4 contents with a correct header"
      );

      info("Testing decompression of an empty file (no header)");
      {
        const n = await IOUtils.writeUTF8(tmpFileName, "");
        ok(n === 0, "Overwrote with empty file");
      }
      await Assert.rejects(
        IOUtils.readUTF8(tmpFileName, { decompress: true }),
        /NotReadableError: Could not read `.*': could not decompress file: buffer is too small $NS_ERROR_FILE_CORRUPTED$/,
        "IOUtils::readUTF8 fails to decompress empty files"
      );

      await cleanup(tmpFileName);
    });

    add_task(async function test_skipBOM() {
      const tmpFileName = PathUtils.join(PathUtils.tempDir, "test_ioutils_readutf8_bom.tmp");

      const raw = `\uFEFFstring`;

      await IOUtils.writeUTF8(tmpFileName, raw);

      is(
        await IOUtils.readUTF8(tmpFileName),
        "string",
        "IOUtils.readUTF8 should skip BOM by default"
      );

      await IOUtils.writeUTF8(tmpFileName, raw, { compress: true });

      is(
        await IOUtils.readUTF8(tmpFileName, { decompress: true }),
        "string",
        "IOUtils.readUTF8 should skip BOM by default for compressed files"
      );

      await cleanup(tmpFileName);
    });
  </script>
</head>

<body>
  <p id="display"></p>
  <div id="content" style="display: none"></div>
  <pre id="test"></pre>
</body>

</html>

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