feat: add support for LUMIGO_DEBUG_SPANDUMP to print to console.log/error

README.md

@@ -98,7 +98,7 @@ Specifically supported are:
 
 * `LUMIGO_TRACER_TOKEN=<token>`: Configure the Lumigo token to enable to upload of telemetry to Lumigo; without this environment variable, your Node.js process will not send telemetry to Lumigo.
 * `LUMIGO_DEBUG=TRUE`: Enables debug logging
-* `LUMIGO_DEBUG_SPANDUMP=<path>`: Log all spans collected to the `<path>` file; this is an option intended only for debugging purposes and should *not* be used in production.
+* `LUMIGO_DEBUG_SPANDUMP=<path|console:log|console:error>`: Log all spans collected to the `<path>` file or, the value is `console:log` or `console:error`, to `console.log` or `console.error`; this is an option intended only for debugging purposes and should *not* be used in production.
 This setting is independent from `LUMIGO_DEBUG`, that is, `LUMIGO_DEBUG` does not need to additionally be set for `LUMIGO_DEBUG_SPANDUMP` to work.
 * `LUMIGO_SWITCH_OFF=TRUE`: This option disables the Lumigo OpenTelemetry Distro entirely; no instrumentation will be injected, no tracing data will be collected.
 * `LUMIGO_SECRET_MASKING_REGEX='["regex1", "regex2"]'`: Prevents Lumigo from sending keys that match the supplied regular expressions in process environment data, HTTP headers, payloads and queries. All regular expressions are case-insensitive. The "magic" value `all` will redact everything. By default, Lumigo applies the following regular expressions: `[".*pass.*", ".*key.*", ".*secret.*", ".*credential.*", ".*passphrase.*"]`. More fine-grained settings can be applied via the following environment variables, which will override `LUMIGO_SECRET_MASKING_REGEX` for a specific type of data:

package.json

@@ -67,6 +67,7 @@
     "jest-chain": "^1.1.6",
     "jest-expect-message": "^1.1.3",
     "jest-json": "^2.0.0",
+    "jest-mock-console": "^2.0.0",
     "jest-summarizing-reporter": "^1.1.4",
     "log-timestamp": "^0.3.0",
     "mock-fs": "^5.2.0",

src/exporters/FileSpanExporter.test.ts

@@ -1,6 +1,7 @@
 import { BasicTracerProvider, SimpleSpanProcessor } from '@opentelemetry/sdk-trace-base';
 import { Span, SpanKind } from '@opentelemetry/api';
 import mock from 'mock-fs';
+import mockConsole from 'jest-mock-console';
 
 import { FileSpanExporter } from './index';
 
@@ -51,6 +52,64 @@ describe('FileSpanExporter tests', () => {
     );
   });
 
+  test('should write one span to console.log', async () => {
+    const restoreConsole = mockConsole();
+    try {
+      const exporterUnderTest = new FileSpanExporter('console:log');
+
+      const provider = new BasicTracerProvider();
+      provider.addSpanProcessor(new SimpleSpanProcessor(exporterUnderTest));
+
+      const root: Span = provider.getTracer('default').startSpan('root');
+      root.setAttribute('foo', 'bar');
+      root.end();
+
+      await provider.shutdown();
+
+      expect(console.log).toHaveBeenCalledTimes(1);
+      const actualSpan = console.log.mock.calls[0][0];
+
+      expect(JSON.parse(actualSpan)).toEqual(
+        expect.objectContaining({
+          name: 'root',
+          attributes: { foo: 'bar' },
+          kind: SpanKind.INTERNAL,
+        })
+      );
+    } finally {
+      restoreConsole();
+    }
+  });
+
+  test('should write one span to console error', async () => {
+    const restoreConsole = mockConsole();
+    try {
+      const exporterUnderTest = new FileSpanExporter('console:error');
+
+      const provider = new BasicTracerProvider();
+      provider.addSpanProcessor(new SimpleSpanProcessor(exporterUnderTest));
+
+      const root: Span = provider.getTracer('default').startSpan('root');
+      root.setAttribute('foo', 'bar');
+      root.end();
+
+      await provider.shutdown();
+
+      expect(console.error).toHaveBeenCalledTimes(1);
+      const actualSpan = console.error.mock.calls[0][0];
+
+      expect(JSON.parse(actualSpan)).toEqual(
+        expect.objectContaining({
+          name: 'root',
+          attributes: { foo: 'bar' },
+          kind: SpanKind.INTERNAL,
+        })
+      );
+    } finally {
+      restoreConsole();
+    }
+  });
+
   test('should write two spans to file', async () => {
     const tmpFile = './test-spans.json';
 

src/exporters/FileSpanExporter.ts

@@ -31,6 +31,9 @@ import { logger } from '../logging';
  * exporter in production.
  */
 
+const PRINT_SPANS_TO_CONSOLE_LOG = 'console:log';
+const PRINT_SPANS_TO_CONSOLE_ERROR = 'console:error';
+
 /* eslint-disable no-console */
 export class FileSpanExporter implements SpanExporter {
   private readonly file: string;
@@ -39,8 +42,11 @@ export class FileSpanExporter implements SpanExporter {
 
   constructor(file: string) {
     this.file = file;
-    this._fd = openSync(file, 'w');
-    this._shutdownOnce = new BindOnceFuture(this._shutdown.bind(this), this);
+
+    if (![PRINT_SPANS_TO_CONSOLE_LOG, PRINT_SPANS_TO_CONSOLE_ERROR].includes(file)) {
+      this._fd = openSync(file, 'w');
+      this._shutdownOnce = new BindOnceFuture(this._shutdown.bind(this), this);
+    }
   }
 
   /**
@@ -59,7 +65,13 @@ export class FileSpanExporter implements SpanExporter {
       spans.map((span) => JSON.stringify(this._exportInfo(span), undefined, 0)).join('\n') + '\n';
 
     try {
-      appendFileSync(this._fd, spansJson);
+      if (this._fd) {
+        appendFileSync(this._fd, spansJson);
+      } else if (this.file === PRINT_SPANS_TO_CONSOLE_LOG) {
+        console.log(spansJson);
+      } else if (this.file === PRINT_SPANS_TO_CONSOLE_ERROR) {
+        console.error(spansJson);
+      }
     } catch (err) {
       return resultCallback({
         code: ExportResultCode.FAILED,
@@ -103,7 +115,7 @@ export class FileSpanExporter implements SpanExporter {
    * Shutdown the exporter.
    */
   shutdown(): Promise<void> {
-    return this._shutdownOnce.call();
+    return this._shutdownOnce?.call();
   }
 
   /**
@@ -136,12 +148,14 @@ export class FileSpanExporter implements SpanExporter {
 
   private _flushAll = async (): Promise<void> =>
     new Promise((resolve, reject) => {
-      try {
-        fsyncSync(this._fd);
-      } catch (err) {
-        logger.error(`An error occured while flushing the spandump to file '${this.file}'`, err);
-        reject(err);
-        return;
+      if (this._fd) {
+        try {
+          fsyncSync(this._fd);
+        } catch (err) {
+          logger.error(`An error occured while flushing the spandump to file '${this.file}'`, err);
+          reject(err);
+          return;
+        }
       }
 
       resolve();