feat(std/log): improvements and new log handler (#4674)

1 files changed, 232 insertions, 25 deletions

diff --git a/std/log/handlers_test.ts b/std/log/handlers_test.ts
index 4feffdaf9..13b6de3bd 100644
--- a/std/log/handlers_test.ts
+++ b/std/log/handlers_test.ts
@@ -1,8 +1,12 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 const { test } = Deno;
-import { assertEquals } from "../testing/asserts.ts";
+import { assert, assertEquals, assertThrowsAsync } from "../testing/asserts.ts";
 import { LogLevel, getLevelName, getLevelByName } from "./levels.ts";
-import { BaseHandler } from "./handlers.ts";
+import { BaseHandler, FileHandler, RotatingFileHandler } from "./handlers.ts";
+import { LogRecord } from "./logger.ts";
+import { existsSync } from "../fs/exists.ts";
+
+const LOG_FILE = "./test_log.file";
 
 class TestHandler extends BaseHandler {
   public messages: string[] = [];
@@ -47,13 +51,9 @@ test(function simpleHandler(): void {
 
     for (const levelName in LogLevel) {
       const level = getLevelByName(levelName);
-      handler.handle({
-        msg: `${levelName.toLowerCase()}-test`,
-        args: [],
-        datetime: new Date(),
-        level: level,
-        levelName: levelName,
-      });
+      handler.handle(
+        new LogRecord(`${levelName.toLowerCase()}-test`, [], level)
+      );
     }
 
     assertEquals(handler.level, testCase);
@@ -67,13 +67,7 @@ test(function testFormatterAsString(): void {
     formatter: "test {levelName} {msg}",
   });
 
-  handler.handle({
-    msg: "Hello, world!",
-    args: [],
-    datetime: new Date(),
-    level: LogLevel.DEBUG,
-    levelName: "DEBUG",
-  });
+  handler.handle(new LogRecord("Hello, world!", [], LogLevel.DEBUG));
 
   assertEquals(handler.messages, ["test DEBUG Hello, world!"]);
 });
@@ -81,16 +75,229 @@ test(function testFormatterAsString(): void {
 test(function testFormatterAsFunction(): void {
   const handler = new TestHandler("DEBUG", {
     formatter: (logRecord): string =>
-      `fn formmatter ${logRecord.levelName} ${logRecord.msg}`,
+      `fn formatter ${logRecord.levelName} ${logRecord.msg}`,
   });
 
-  handler.handle({
-    msg: "Hello, world!",
-    args: [],
-    datetime: new Date(),
-    level: LogLevel.ERROR,
-    levelName: "ERROR",
-  });
+  handler.handle(new LogRecord("Hello, world!", [], LogLevel.ERROR));
+
+  assertEquals(handler.messages, ["fn formatter ERROR Hello, world!"]);
+});
+
+test({
+  name: "FileHandler with mode 'w' will wipe clean existing log file",
+  async fn() {
+    const fileHandler = new FileHandler("WARNING", {
+      filename: LOG_FILE,
+      mode: "w",
+    });
+
+    await fileHandler.setup();
+    fileHandler.handle(new LogRecord("Hello World", [], LogLevel.WARNING));
+    await fileHandler.destroy();
+    const firstFileSize = (await Deno.stat(LOG_FILE)).size;
+
+    await fileHandler.setup();
+    fileHandler.handle(new LogRecord("Hello World", [], LogLevel.WARNING));
+    await fileHandler.destroy();
+    const secondFileSize = (await Deno.stat(LOG_FILE)).size;
+
+    assertEquals(secondFileSize, firstFileSize);
+    Deno.removeSync(LOG_FILE);
+  },
+});
+
+test({
+  name: "FileHandler with mode 'x' will throw if log file already exists",
+  async fn() {
+    await assertThrowsAsync(
+      async () => {
+        Deno.writeFileSync(LOG_FILE, new TextEncoder().encode("hello world"));
+        const fileHandler = new FileHandler("WARNING", {
+          filename: LOG_FILE,
+          mode: "x",
+        });
+        await fileHandler.setup();
+      },
+      Deno.errors.AlreadyExists,
+      "ile exists"
+    );
+    Deno.removeSync(LOG_FILE);
+  },
+});
+
+test({
+  name:
+    "RotatingFileHandler with mode 'w' will wipe clean existing log file and remove others",
+  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("WARNING", {
+      filename: LOG_FILE,
+      maxBytes: 50,
+      maxBackupCount: 3,
+      mode: "w",
+    });
+    await fileHandler.setup();
+    await 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);
+  },
+});
+
+test({
+  name:
+    "RotatingFileHandler with mode 'x' will throw if any log file already exists",
+  async fn() {
+    await assertThrowsAsync(
+      async () => {
+        Deno.writeFileSync(
+          LOG_FILE + ".3",
+          new TextEncoder().encode("hello world")
+        );
+        const fileHandler = new RotatingFileHandler("WARNING", {
+          filename: LOG_FILE,
+          maxBytes: 50,
+          maxBackupCount: 3,
+          mode: "x",
+        });
+        await fileHandler.setup();
+      },
+      Deno.errors.AlreadyExists,
+      "Backup log file " + LOG_FILE + ".3 already exists"
+    );
+    Deno.removeSync(LOG_FILE + ".3");
+    Deno.removeSync(LOG_FILE);
+  },
+});
+
+test({
+  name: "RotatingFileHandler with first rollover",
+  async fn() {
+    const fileHandler = new RotatingFileHandler("WARNING", {
+      filename: LOG_FILE,
+      maxBytes: 25,
+      maxBackupCount: 3,
+      mode: "w",
+    });
+    await fileHandler.setup();
+
+    fileHandler.handle(new LogRecord("AAA", [], LogLevel.ERROR)); // 'ERROR AAA\n' = 10 bytes
+    assertEquals((await Deno.stat(LOG_FILE)).size, 10);
+    fileHandler.handle(new LogRecord("AAA", [], LogLevel.ERROR));
+    assertEquals((await Deno.stat(LOG_FILE)).size, 20);
+    fileHandler.handle(new LogRecord("AAA", [], LogLevel.ERROR));
+    // 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);
+
+    await fileHandler.destroy();
+
+    Deno.removeSync(LOG_FILE);
+    Deno.removeSync(LOG_FILE + ".1");
+  },
+});
+
+test({
+  name: "RotatingFileHandler with all backups rollover",
+  async 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("WARNING", {
+      filename: LOG_FILE,
+      maxBytes: 2,
+      maxBackupCount: 3,
+      mode: "a",
+    });
+    await fileHandler.setup();
+    fileHandler.handle(new LogRecord("AAA", [], LogLevel.ERROR)); // 'ERROR AAA\n' = 10 bytes
+    await 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");
+  },
+});
+
+test({
+  name: "RotatingFileHandler maxBytes cannot be less than 1",
+  async fn() {
+    await assertThrowsAsync(
+      async () => {
+        const fileHandler = new RotatingFileHandler("WARNING", {
+          filename: LOG_FILE,
+          maxBytes: 0,
+          maxBackupCount: 3,
+          mode: "w",
+        });
+        await fileHandler.setup();
+      },
+      Error,
+      "maxBytes cannot be less than 1"
+    );
+  },
+});
 
-  assertEquals(handler.messages, ["fn formmatter ERROR Hello, world!"]);
+test({
+  name: "RotatingFileHandler maxBackupCount cannot be less than 1",
+  async fn() {
+    await assertThrowsAsync(
+      async () => {
+        const fileHandler = new RotatingFileHandler("WARNING", {
+          filename: LOG_FILE,
+          maxBytes: 50,
+          maxBackupCount: 0,
+          mode: "w",
+        });
+        await fileHandler.setup();
+      },
+      Error,
+      "maxBackupCount cannot be less than 1"
+    );
+  },
 });