feat(logger): added support for custom logger

fix #2
grantila · Mar 3, 2021 · 0d1df76 · 0d1df76
1 parent 976f9ff
commit 0d1df76
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Showing 8 changed files with 127 additions and 44 deletions.
diff --git a/README.md b/README.md
@@ -111,6 +111,12 @@ You can also use `npx`:
 <head><script src="https://cdn.jsdelivr.net/npm/trace-unhandled@latest/browser.js"></script></head>
 ```
 
+To specify a custom logger function, use `setTraceUnhandledLogger`:
+
+```ts
+window.setTraceUnhandledLogger( msg => { ... } ); // msg is a string
+```
+
 
 ## Programatically - API
 
@@ -127,6 +133,13 @@ const { register } = require( 'trace-unhandled' );
 register( );
 ```
 
+To specify a custom logger function, use `setLogger`:
+
+```ts
+const { setLogger } = require( 'trace-unhandled' );
+setLogger( msg => { ... } ); // msg is a string
+```
+
 
 ## In unit tests
 

diff --git a/index.ts b/index.ts
@@ -1,2 +1,2 @@
-
+export { LoggerFunction, setLogger } from './lib/core';
 export const register = ( ) => require( './lib/register' );
diff --git a/jest.config.js b/jest.config.js
@@ -2,4 +2,5 @@ module.exports = {
   testEnvironment: "node",
   testMatch: ['<rootDir>/test/**/*.spec.js'],
   coverageReporters: ["lcov", "text", "html"],
+  coveragePathIgnorePatterns: [ '/node_modules/', '/test/' ],
 };
diff --git a/lib/core.ts b/lib/core.ts
@@ -54,6 +54,20 @@ function mergeErrors( traceError: Error, mainError?: Error )
 		errorLines.slice( 0, i ).reverse( ).join( "\n" );
 }
 
+function defaultLogger( msg: string )
+{
+	console.error( msg );
+}
+
+export type LoggerFunction = ( msg: string ) => void;
+
+let loggerFunction: LoggerFunction = defaultLogger;
+
+export function setLogger( loggerFn: LoggerFunction )
+{
+	loggerFunction = loggerFn ?? defaultLogger;
+}
+
 export function logger(
 	reason: Error | undefined,
 	promise: TraceablePromise< any >,
@@ -69,7 +83,7 @@ export function logger(
 
 	const prefix = pid == null ? '' : `(node:${pid}) `;
 
-	console.error(
+	loggerFunction(
 		`${prefix}UnhandledPromiseRejectionWarning\n` +
 		(
 			!promise.__tracedError

diff --git a/test/helpers.js b/test/helpers.js
@@ -0,0 +1,41 @@
+const { Finally, Try, delay } = require( 'already' );
+
+module.exports.withConsoleSpy = fn => async ( ) =>
+{
+	const oldError = console.error;
+	console.error = jest.fn( );
+	return Try( fn )
+		.then( ...Finally( ( ) =>
+		{
+			console.error = oldError;
+		} ) );
+}
+
+module.exports.triggerUnhandledWarnings =
+	async function triggerUnhandledWarnings( )
+{
+	await delay( 0 );
+	global.gc && global.gc( );
+	await delay( 0 );
+}
+
+module.exports.splitLines = function splitLines( lines )
+{
+	return [ ].concat( ...lines.map( line => line.split( "\n" ) ) );
+}
+
+module.exports.cutColumn = function cutColumn( line )
+{
+	const m = line.match( /(.*:\d+):\d+\)?$/ );
+	if ( !m )
+		return line;
+	return m[ 1 ];
+}
+
+module.exports.cutLocation = function cutLocation( line )
+{
+	const m = line.match( /(.*):\d+:\d+\)?$/ );
+	if ( !m )
+		return line;
+	return m[ 1 ];
+}
diff --git a/test/logger.spec.js b/test/logger.spec.js
@@ -0,0 +1,44 @@
+
+const index = require( '../dist/index' );
+const {
+	triggerUnhandledWarnings,
+	splitLines,
+	cutColumn,
+} = require( './helpers' );
+
+
+describe( "logger", ( ) =>
+{
+	it( "setLogger", async ( ) =>
+	{
+		const logger = jest.fn( );
+		index.setLogger( logger );
+		index.register( );
+
+		const err = new Error( "foobar" );
+
+		new Promise( ( resolve, reject ) =>
+		{
+			throw err;
+		} );
+
+		await triggerUnhandledWarnings( );
+
+		index.setLogger( );
+
+		const linesWoColumns = splitLines( logger.mock.calls[ 0 ] )
+			.filter( line => line.includes( "logger.spec.js" ) )
+			.map( line => cutColumn( line ) );
+
+		const errorAndShared = splitLines( logger.mock.calls[ 0 ] )
+			.filter( line => line );
+
+		expect( linesWoColumns.length ).toBeGreaterThanOrEqual( 2 );
+		expect( linesWoColumns[ 0 ] ).not.toBe( linesWoColumns[ 1 ] );
+
+		expect( errorAndShared )
+			.toContain( "    ==== Error at: ====================" );
+			expect( errorAndShared )
+			.toContain( "    ==== Shared trace: ================" );
+	} );
+} );
diff --git a/test/register.spec.js b/test/register.spec.js
@@ -1,45 +1,14 @@
 
-const { Finally, Try, delay } = require( 'already' );
-require( '../register' );
-
-const withConsoleSpy = fn => async ( ) =>
-{
-	const oldError = console.error;
-	console.error = jest.fn( );
-	return Try( fn )
-		.then( ...Finally( ( ) =>
-		{
-			console.error = oldError;
-		} ) );
-}
+const {
+	withConsoleSpy,
+	triggerUnhandledWarnings,
+	splitLines,
+	cutColumn,
+	cutLocation,
+} = require( './helpers' );
 
-async function triggerUnhandledWarnings( )
-{
-	await delay( 0 );
-	global.gc && global.gc( );
-	await delay( 0 );
-}
-
-function splitLines( lines )
-{
-	return [ ].concat( ...lines.map( line => line.split( "\n" ) ) );
-}
-
-function cutColumn( line )
-{
-	const m = line.match( /(.*:\d+):\d+\)?$/ );
-	if ( !m )
-		return line;
-	return m[ 1 ];
-}
+require( '../register' );
 
-function cutLocation( line )
-{
-	const m = line.match( /(.*):\d+:\d+\)?$/ );
-	if ( !m )
-		return line;
-	return m[ 1 ];
-}
 
 describe( "register", ( ) =>
 {
@@ -151,7 +120,7 @@ describe( "register", ( ) =>
 		const errorAndShared = splitLines( console.error.mock.calls[ 0 ] )
 			.filter( line => line );
 
-		expect( linesWoColumns.length ).toBeGreaterThanOrEqual( 2 );
+		expect( linesWoColumns.length ).toBeGreaterThanOrEqual( 1 );
 		expect( linesWoColumns[ 0 ] ).not.toBe( linesWoColumns[ 1 ] );
 
 		expect( errorAndShared[ errorAndShared.length - 2 ] ).toBe(
@@ -180,7 +149,7 @@ describe( "register", ( ) =>
 		const errorAndShared = splitLines( console.error.mock.calls[ 0 ] )
 			.filter( line => line );
 
-		expect( linesWoColumns.length ).toBeGreaterThanOrEqual( 2 );
+		expect( linesWoColumns.length ).toBeGreaterThanOrEqual( 1 );
 		expect( linesWoColumns[ 0 ] ).not.toBe( linesWoColumns[ 1 ] );
 
 		expect( errorAndShared[ errorAndShared.length - 2 ] ).toBe(

diff --git a/web/register-web.ts b/web/register-web.ts
@@ -1,9 +1,10 @@
 
-import { logger, TraceablePromise } from "../lib/core";
+import { logger, TraceablePromise, setLogger} from "../lib/core";
 
 window.onunhandledrejection = function( event: PromiseRejectionEvent )
 {
 	logger( event.reason, event.promise );
 };
 
 ( < any >window ).Promise = TraceablePromise;
+( < any >window ).setTraceUnhandledLogger = setLogger;