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// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.import {  assert,  assertEquals,  assertNotEquals,  assertThrows,} from "../assert/mod.ts";import { LogLevels } from "./levels.ts";import { RotatingFileHandler } from "./rotating_file_handler.ts";import { LogRecord } from "./logger.ts";import { existsSync } from "../fs/exists.ts";
const LOG_FILE = "./rotating_file_handler_test_log.file";
Deno.test({  name:    "RotatingFileHandler wipes existing log file clean and removes others with mode 'w'",  async fn() {    Deno.writeFileSync(LOG_FILE, new TextEncoder().encode("hello world"));    Deno.writeFileSync(      LOG_FILE + ".1",      new TextEncoder().encode("hello world"),    );    Deno.writeFileSync(      LOG_FILE + ".2",      new TextEncoder().encode("hello world"),    );    Deno.writeFileSync(      LOG_FILE + ".3",      new TextEncoder().encode("hello world"),    );
    const fileHandler = new RotatingFileHandler("WARN", {      filename: LOG_FILE,      maxBytes: 50,      maxBackupCount: 3,      mode: "w",    });    fileHandler.setup();    fileHandler.destroy();
    assertEquals((await Deno.stat(LOG_FILE)).size, 0);    assert(!existsSync(LOG_FILE + ".1"));    assert(!existsSync(LOG_FILE + ".2"));    assert(!existsSync(LOG_FILE + ".3"));
    Deno.removeSync(LOG_FILE);  },});
Deno.test({  name:    "RotatingFileHandler throws if any log file already exists with mode 'x'",  fn() {    Deno.writeFileSync(      LOG_FILE + ".3",      new TextEncoder().encode("hello world"),    );    using fileHandler = new RotatingFileHandler("WARN", {      filename: LOG_FILE,      maxBytes: 50,      maxBackupCount: 3,      mode: "x",    });    assertThrows(      () => {        fileHandler.setup();      },      Deno.errors.AlreadyExists,      "Backup log file " + LOG_FILE + ".3 already exists",    );
    Deno.removeSync(LOG_FILE + ".3");    Deno.removeSync(LOG_FILE);  },});
Deno.test({  name: "RotatingFileHandler handles first rollover, monitor step by step",  async fn() {    using fileHandler = new RotatingFileHandler("WARN", {      filename: LOG_FILE,      maxBytes: 25,      maxBackupCount: 3,      mode: "w",    });    fileHandler.setup();
    fileHandler.handle(      new LogRecord({        msg: "AAA",        args: [],        level: LogLevels.ERROR,        loggerName: "default",      }),    ); // 'ERROR AAA\n' = 10 bytes    fileHandler.flush();    assertEquals((await Deno.stat(LOG_FILE)).size, 10);    fileHandler.handle(      new LogRecord({        msg: "AAA",        args: [],        level: LogLevels.ERROR,        loggerName: "default",      }),    );    fileHandler.flush();    assertEquals((await Deno.stat(LOG_FILE)).size, 20);    fileHandler.handle(      new LogRecord({        msg: "AAA",        args: [],        level: LogLevels.ERROR,        loggerName: "default",      }),    );    fileHandler.flush();    // Rollover occurred. Log file now has 1 record, rollover file has the original 2    assertEquals((await Deno.stat(LOG_FILE)).size, 10);    assertEquals((await Deno.stat(LOG_FILE + ".1")).size, 20);
    Deno.removeSync(LOG_FILE);    Deno.removeSync(LOG_FILE + ".1");  },});
Deno.test({  name: "RotatingFileHandler handles first rollover, check all at once",  async fn() {    const fileHandler = new RotatingFileHandler("WARN", {      filename: LOG_FILE,      maxBytes: 25,      maxBackupCount: 3,      mode: "w",    });    fileHandler.setup();
    fileHandler.handle(      new LogRecord({        msg: "AAA",        args: [],        level: LogLevels.ERROR,        loggerName: "default",      }),    ); // 'ERROR AAA\n' = 10 bytes    fileHandler.handle(      new LogRecord({        msg: "AAA",        args: [],        level: LogLevels.ERROR,        loggerName: "default",      }),    );    fileHandler.handle(      new LogRecord({        msg: "AAA",        args: [],        level: LogLevels.ERROR,        loggerName: "default",      }),    );
    fileHandler.destroy();
    assertEquals((await Deno.stat(LOG_FILE)).size, 10);    assertEquals((await Deno.stat(LOG_FILE + ".1")).size, 20);
    Deno.removeSync(LOG_FILE);    Deno.removeSync(LOG_FILE + ".1");  },});
Deno.test({  name: "RotatingFileHandler handles all backups rollover",  fn() {    Deno.writeFileSync(LOG_FILE, new TextEncoder().encode("original log file"));    Deno.writeFileSync(      LOG_FILE + ".1",      new TextEncoder().encode("original log.1 file"),    );    Deno.writeFileSync(      LOG_FILE + ".2",      new TextEncoder().encode("original log.2 file"),    );    Deno.writeFileSync(      LOG_FILE + ".3",      new TextEncoder().encode("original log.3 file"),    );
    const fileHandler = new RotatingFileHandler("WARN", {      filename: LOG_FILE,      maxBytes: 2,      maxBackupCount: 3,      mode: "a",    });    fileHandler.setup();    fileHandler.handle(      new LogRecord({        msg: "AAA",        args: [],        level: LogLevels.ERROR,        loggerName: "default",      }),    ); // 'ERROR AAA\n' = 10 bytes    fileHandler.destroy();
    const decoder = new TextDecoder();    assertEquals(decoder.decode(Deno.readFileSync(LOG_FILE)), "ERROR AAA\n");    assertEquals(      decoder.decode(Deno.readFileSync(LOG_FILE + ".1")),      "original log file",    );    assertEquals(      decoder.decode(Deno.readFileSync(LOG_FILE + ".2")),      "original log.1 file",    );    assertEquals(      decoder.decode(Deno.readFileSync(LOG_FILE + ".3")),      "original log.2 file",    );    assert(!existsSync(LOG_FILE + ".4"));
    Deno.removeSync(LOG_FILE);    Deno.removeSync(LOG_FILE + ".1");    Deno.removeSync(LOG_FILE + ".2");    Deno.removeSync(LOG_FILE + ".3");  },});
Deno.test({  name: "RotatingFileHandler handles maxBytes less than 1",  fn() {    assertThrows(      () => {        const fileHandler = new RotatingFileHandler("WARN", {          filename: LOG_FILE,          maxBytes: 0,          maxBackupCount: 3,          mode: "w",        });        fileHandler.setup();      },      Error,      "maxBytes cannot be less than 1",    );  },});
Deno.test({  name: "RotatingFileHandler handles maxBackupCount less than 1",  fn() {    assertThrows(      () => {        const fileHandler = new RotatingFileHandler("WARN", {          filename: LOG_FILE,          maxBytes: 50,          maxBackupCount: 0,          mode: "w",        });        fileHandler.setup();      },      Error,      "maxBackupCount cannot be less than 1",    );  },});
Deno.test({  name: "RotatingFileHandler rotates on byte length, not msg length",  async fn() {    const fileHandler = new RotatingFileHandler("WARN", {      filename: LOG_FILE,      maxBytes: 7,      maxBackupCount: 1,      mode: "w",    });    fileHandler.setup();
    const msg = "。";    const msgLength = msg.length;    const msgByteLength = new TextEncoder().encode(msg).byteLength;    assertNotEquals(msgLength, msgByteLength);    assertEquals(msgLength, 1);    assertEquals(msgByteLength, 3);
    fileHandler.log(msg); // logs 4 bytes (including '\n')    fileHandler.log(msg); // max bytes is 7, but this would be 8.  Rollover.
    fileHandler.destroy();
    const fileSize1 = (await Deno.stat(LOG_FILE)).size;    const fileSize2 = (await Deno.stat(LOG_FILE + ".1")).size;
    assertEquals(fileSize1, msgByteLength + 1);    assertEquals(fileSize2, msgByteLength + 1);
    Deno.removeSync(LOG_FILE);    Deno.removeSync(LOG_FILE + ".1");  },});
Deno.test({  name: "RotatingFileHandler handles strings larger than the buffer",  fn() {    const fileHandler = new RotatingFileHandler("WARN", {      filename: LOG_FILE,      mode: "w",      maxBytes: 4000000,      maxBackupCount: 10,    });    const logOverBufferLimit = "A".repeat(4096);    fileHandler.setup();
    fileHandler.log(logOverBufferLimit);    fileHandler.destroy();
    assertEquals(      Deno.readTextFileSync(LOG_FILE),      `${logOverBufferLimit}\n`,    );
    Deno.removeSync(LOG_FILE);  },});
Deno.test({  name: "RotatingFileHandler handles a mixture of string sizes",  fn() {    const fileHandler = new RotatingFileHandler("WARN", {      filename: LOG_FILE,      mode: "w",      maxBytes: 4000000,      maxBackupCount: 10,    });    const veryLargeLog = "A".repeat(10000);    const regularLog = "B".repeat(100);    fileHandler.setup();
    fileHandler.log(regularLog);    fileHandler.log(veryLargeLog);    fileHandler.log(regularLog);    fileHandler.destroy();
    assertEquals(      Deno.readTextFileSync(LOG_FILE),      `${regularLog}\n${veryLargeLog}\n${regularLog}\n`,    );
    Deno.removeSync(LOG_FILE);  },});