[wrangler] Make WRANGLER_LOG more lenient and fallback to log (#2840

)

* Make `WRANGLER_LOG` more lenient and fallback to `log`

Previously, levels set via the `WRANGLER_LOG` environment-variable
were case-sensitive. If an unexpected level was set, Wrangler would
fallback to `none`, hiding all logs. The fallback has now been
switched to `log`, and lenient case-insensitive matching is used when
setting the level.

* fixup! Make `WRANGLER_LOG` more lenient and fallback to `log`

.changeset/four-toes-lay.md

@@ -0,0 +1,9 @@
+---
+"wrangler": patch
+---
+
+fix: make `WRANGLER_LOG` case-insensitive, warn on unexpected values, and fallback to `log` if invalid
+
+Previously, levels set via the `WRANGLER_LOG` environment-variable were case-sensitive.
+If an unexpected level was set, Wrangler would fallback to `none`, hiding all logs.
+The fallback has now been switched to `log`, and lenient case-insensitive matching is used when setting the level.

packages/wrangler/src/__tests__/logger.test.ts

@@ -1,10 +1,11 @@
-import { logger } from "../logger";
+import { Logger } from "../logger";
 import { mockConsoleMethods } from "./helpers/mock-console";
 
 describe("logger", () => {
 	const std = mockConsoleMethods();
 
 	it("should add colored markers to error and warning messages", () => {
+		const logger = new Logger();
 		logger.loggerLevel = "debug";
 		logger.debug("This is a debug message");
 		logger.log("This is a log message");
@@ -27,6 +28,7 @@ describe("logger", () => {
 
 	describe("loggerLevel=debug", () => {
 		it("should render messages that are at or above the log level set in the logger", () => {
+			const logger = new Logger();
 			logger.loggerLevel = "debug";
 			logger.debug("This is a debug message");
 			logger.log("This is a log message");
@@ -50,6 +52,7 @@ describe("logger", () => {
 
 	describe("loggerLevel=log", () => {
 		it("should render messages that are at or above the log level set in the logger", () => {
+			const logger = new Logger();
 			logger.loggerLevel = "log";
 			logger.debug("This is a debug message");
 			logger.log("This is a log message");
@@ -73,6 +76,7 @@ describe("logger", () => {
 
 	describe("loggerLevel=warn", () => {
 		it("should render messages that are at or above the log level set in the logger", () => {
+			const logger = new Logger();
 			logger.loggerLevel = "warn";
 			logger.debug("This is a debug message");
 			logger.log("This is a log message");
@@ -96,6 +100,7 @@ describe("logger", () => {
 
 	describe("loggerLevel=error", () => {
 		it("should render messages that are at or above the log level set in the logger", () => {
+			const logger = new Logger();
 			logger.loggerLevel = "error";
 			logger.debug("This is a debug message");
 			logger.log("This is a log message");
@@ -122,7 +127,7 @@ describe("logger", () => {
 		});
 
 		it("should render messages that are at or above the log level set in the env var", () => {
-			logger.loggerLevel = "error";
+			const logger = new Logger();
 			logger.debug("This is a debug message");
 			logger.log("This is a log message");
 			logger.warn("This is a warn message");
@@ -138,4 +143,65 @@ describe("logger", () => {
       `);
 		});
 	});
+
+	describe("loggerLevelFromEnvVar case-insensitive", () => {
+		beforeEach(() => {
+			process.env.WRANGLER_LOG = "wARn";
+		});
+		afterEach(() => {
+			process.env.WRANGLER_LOG = undefined;
+		});
+
+		it("should render messages that are at or above the log level set in the env var", () => {
+			const logger = new Logger();
+			logger.debug("This is a debug message");
+			logger.log("This is a log message");
+			logger.warn("This is a warn message");
+			logger.error("This is a error message");
+
+			expect(std.debug).toMatchInlineSnapshot(`""`);
+			expect(std.out).toMatchInlineSnapshot(`""`);
+			expect(std.warn).toMatchInlineSnapshot(`
+        "▲ [WARNING] This is a warn message
+
+        "
+      `);
+			expect(std.err).toMatchInlineSnapshot(`
+        "X [ERROR] This is a error message
+
+        "
+      `);
+		});
+	});
+
+	describe("loggerLevelFromEnvVar falls back to log on invalid level", () => {
+		beforeEach(() => {
+			process.env.WRANGLER_LOG = "everything";
+		});
+		afterEach(() => {
+			process.env.WRANGLER_LOG = undefined;
+		});
+
+		it("should render messages that are at or above the log level set in the env var", () => {
+			const logger = new Logger();
+			logger.debug("This is a debug message");
+			logger.log("This is a log message");
+			logger.warn("This is a warn message");
+			logger.error("This is a error message");
+
+			expect(std.debug).toMatchInlineSnapshot(`""`);
+			expect(std.out).toMatchInlineSnapshot(`"This is a log message"`);
+			expect(std.warn).toMatchInlineSnapshot(`
+        "Unrecognised WRANGLER_LOG value \\"everything\\", expected \\"none\\" | \\"error\\" | \\"warn\\" | \\"info\\" | \\"log\\" | \\"debug\\", defaulting to \\"log\\"...
+        ▲ [WARNING] This is a warn message
+
+        "
+      `);
+			expect(std.err).toMatchInlineSnapshot(`
+        "X [ERROR] This is a error message
+
+        "
+      `);
+		});
+	});
 });

packages/wrangler/src/logger.ts

@@ -26,15 +26,30 @@ const LOGGER_LEVEL_FORMAT_TYPE_MAP = {
 
 const getLogLevelFromEnv = getEnvironmentVariableFactory({
 	variableName: "WRANGLER_LOG",
-	defaultValue: () => "log",
 });
 
+function getLoggerLevel(): LoggerLevel {
+	const fromEnv = getLogLevelFromEnv()?.toLowerCase();
+	if (fromEnv !== undefined) {
+		if (fromEnv in LOGGER_LEVELS) return fromEnv as LoggerLevel;
+		const expected = Object.keys(LOGGER_LEVELS)
+			.map((level) => `"${level}"`)
+			.join(" | ");
+		console.warn(
+			`Unrecognised WRANGLER_LOG value ${JSON.stringify(
+				fromEnv
+			)}, expected ${expected}, defaulting to "log"...`
+		);
+	}
+	return "log";
+}
+
 export type TableRow<Keys extends string> = Record<Keys, string>;
 
-class Logger {
+export class Logger {
 	constructor() {}
 
-	loggerLevel: LoggerLevel = (getLogLevelFromEnv() as LoggerLevel) ?? "log";
+	loggerLevel = getLoggerLevel();
 	columns = process.stdout.columns;
 
 	debug = (...args: unknown[]) => this.doLog("debug", args);