bug detectors: fix error stack and the error message of the finding

- remove internal libraries from the stack trace of the finding
- add tests for double-printed finding messages

Author: oetr

packages/core/core.ts

@@ -335,6 +335,9 @@ function cleanErrorStack(error: Error): string {
 		if (index !== undefined && index >= 0) {
 			error.stack = stack.slice(index + 1).join("\n");
 		}
+
+		// also delete all lines that mention "jazzer.js/packages/"
+		error.stack = error.stack.replace(/.*jazzer.js\/packages\/.*\n/g, "");
 	}
 
 	const result: string[] = [];

packages/jest-runner/worker.ts

@@ -212,9 +212,6 @@ export class JazzerWorker {
 				// Mark fuzzer tests as skipped and not as error.
 				if (error instanceof FuzzerStartError) {
 					skipTest = true;
-				} else if (error instanceof Finding) {
-					// Add error message to the top of the stack trace---Jest will print it at the top.
-					error.stack = error.message + "\n" + error.stack;
 				}
 				errors.push(error);
 			});

tests/bug-detectors/bug-detectors.test.js

@@ -30,6 +30,14 @@ describe("General tests", () => {
 	const bugDetectorDirectory = path.join(__dirname, "general");
 	const friendlyFilePath = path.join(bugDetectorDirectory, "FRIENDLY");
 	const evilFilePath = path.join(bugDetectorDirectory, "jaz_zer");
+	const errorPattern =
+		/Command Injection in execSync\(\): called with 'jaz_zer'/g;
+
+	function expectErrorToBePrintedOnce(output) {
+		const matches = output.match(errorPattern);
+		expect(matches).toBeTruthy();
+		expect(matches.length).toBe(1);
+	}
 
 	// Delete files created by the tests.
 	beforeEach(() => {
@@ -48,6 +56,8 @@ describe("General tests", () => {
 			fuzzTest.execute();
 		}).toThrow(FuzzingExitCode);
 		expect(fs.existsSync(friendlyFilePath)).toBeFalsy();
+		// check that the stdout has the following line only once: "Command Injection in execSync(): called with 'jaz_zer'"
+		expectErrorToBePrintedOnce(fuzzTest.stdout);
 	});
 
 	it("Call with EVIL string; SYNC", () => {
@@ -60,6 +70,7 @@ describe("General tests", () => {
 			fuzzTest.execute();
 		}).toThrow(FuzzingExitCode);
 		expect(fs.existsSync(friendlyFilePath)).toBeFalsy();
+		expectErrorToBePrintedOnce(fuzzTest.stdout);
 	});
 
 	it("Call with FRIENDLY string; ASYNC", () => {
@@ -92,6 +103,7 @@ describe("General tests", () => {
 			fuzzTest.execute();
 		}).toThrow(FuzzingExitCode);
 		expect(fs.existsSync(friendlyFilePath)).toBeFalsy();
+		expectErrorToBePrintedOnce(fuzzTest.stdout);
 	});
 
 	it("Call with EVIL string; With done callback; With try/catch", () => {
@@ -104,6 +116,7 @@ describe("General tests", () => {
 			fuzzTest.execute();
 		}).toThrow(FuzzingExitCode);
 		expect(fs.existsSync(friendlyFilePath)).toBeFalsy();
+		expectErrorToBePrintedOnce(fuzzTest.stdout);
 	});
 
 	it("Call with EVIL string; With done callback; With timeout", () => {
@@ -192,7 +205,7 @@ describe("General tests", () => {
 			.sync(false)
 			.fuzzEntryPoint("ForkModeCallOriginalEvilAsync")
 			.dir(bugDetectorDirectory)
-			.runs(200)
+			.runs(10)
 			.forkMode(3)
 			.build();
 		fuzzTest.execute();
@@ -242,6 +255,7 @@ describe("General tests", () => {
 			fuzzTest.execute();
 		}).toThrow(JestRegressionExitCode);
 		expect(fs.existsSync(friendlyFilePath)).toBeFalsy();
+		expectErrorToBePrintedOnce(fuzzTest.stderr);
 	});
 
 	it("Jest: Test with EVIL command; ASYNC", () => {
@@ -257,6 +271,7 @@ describe("General tests", () => {
 			fuzzTest.execute();
 		}).toThrow(JestRegressionExitCode);
 		expect(fs.existsSync(friendlyFilePath)).toBeFalsy();
+		expectErrorToBePrintedOnce(fuzzTest.stderr);
 	});
 
 	it("Jest: Test with FRIENDLY command", () => {
@@ -300,6 +315,7 @@ describe("General tests", () => {
 			process.platform === "win32" ? JestRegressionExitCode : FuzzingExitCode
 		);
 		expect(fs.existsSync(friendlyFilePath)).toBeFalsy();
+		expectErrorToBePrintedOnce(fuzzTest.stderr);
 	});
 
 	it("Jest: Fuzzing mode; Test with FRIENDLY command", () => {
@@ -330,6 +346,7 @@ describe("General tests", () => {
 			fuzzTest.execute();
 		}).toThrow(JestRegressionExitCode);
 		expect(fs.existsSync(friendlyFilePath)).toBeFalsy();
+		expectErrorToBePrintedOnce(fuzzTest.stderr);
 	});
 
 	it("Jest: Test with FRIENDLY command; Done callback", () => {