fix: (CN-943) wrap GoFileName error (#772)

* fix: wrap go parser error

Author: ividalATSnyk

.snyk

@@ -5,13 +5,13 @@ ignore:
   SNYK-JS-TAR-15307072:
     - 'snyk-nodejs-lockfile-parser > @yarnpkg/core > tar':
         reason: 'Indirect dependency from snyk-nodejs-lockfile-parser, waiting for upstream fix'
-        expires: 2026-03-26T00:00:00.000Z
+        expires: 2026-04-03T00:00:00.000Z
   SNYK-JS-TAR-15416075:
     - 'snyk-nodejs-lockfile-parser > @yarnpkg/core > tar':
         reason: 'Indirect dependency from snyk-nodejs-lockfile-parser, waiting for upstream fix'
-        expires: 2026-03-26T00:00:00.000Z
+        expires: 2026-04-03T00:00:00.000Z
   SNYK-JS-TAR-15456201:
     - 'snyk-nodejs-lockfile-parser > @yarnpkg/core > tar':
         reason: 'Indirect dependency from snyk-nodejs-lockfile-parser, waiting for upstream fix'
-        expires: 2026-03-26T00:00:00.000Z
+        expires: 2026-04-03T00:00:00.000Z
 patch: {}

lib/go-parser/go-binary.ts

@@ -169,10 +169,7 @@ export class GoBinary {
           // result in the package name "github.com/my/pkg/a".
           const parts = pkgFile.split(modFullName);
           if (parts.length !== 2 || parts[0] !== "") {
-            throw {
-              fileName: pkgFile,
-              moduleName: modFullName,
-            } as GoFileNameError;
+            throw new GoFileNameError(pkgFile, modFullName);
           }
 
           // for files in the "root" of a module
@@ -194,9 +191,17 @@ export class GoBinary {
   }
 }
 
-interface GoFileNameError extends Error {
-  fileName: string;
-  moduleName: string;
+export class GoFileNameError extends Error {
+  public readonly fileName: string;
+  public readonly moduleName: string;
+
+  constructor(fileName: string, moduleName: string) {
+    super();
+    this.name = "GoFileNameError";
+    this.message = `Failed to match Go file "${fileName}" to module "${moduleName}"`;
+    this.fileName = fileName;
+    this.moduleName = moduleName;
+  }
 }
 
 /**

test/unit/go-binaries.spec.ts

@@ -8,6 +8,7 @@ import {
   determinePaths,
   extractModuleInformation,
   GoBinary,
+  GoFileNameError,
   parseGoVersion,
 } from "../../lib/go-parser/go-binary";
 import { GoModule } from "../../lib/go-parser/go-module";
@@ -659,3 +660,77 @@ describe("test path determination", () => {
     expect(vendorPath).toBe("");
   });
 });
+
+describe("GoFileNameError", () => {
+  // Construct a GoBinary from any real fixture so we have a valid instance to
+  // call matchFilesToModules on. We then overwrite modules directly.
+  const goBin = new GoBinary(
+    elf.parse(
+      readFileSync(
+        path.join(__dirname, "../fixtures/go-binaries/go1.13.15_normal"),
+      ),
+    ),
+  );
+
+  const moduleName = "github.com/foo/bar";
+  const moduleVersion = "v1.0.0";
+
+  // Crafting a file path where the module's fullName appears twice causes
+  // pkgFile.split(modFullName) to produce 3 parts, triggering the throw.
+  const duplicatedPath = `${moduleName}@${moduleVersion}/${moduleName}@${moduleVersion}/file.go`;
+
+  beforeEach(() => {
+    goBin.modules = [new GoModule(moduleName, moduleVersion)];
+  });
+
+  it("throws GoFileNameError when a file path cannot be matched to a module", () => {
+    expect(() => goBin.matchFilesToModules([duplicatedPath])).toThrow(
+      GoFileNameError,
+    );
+  });
+
+  it("thrown error is an instance of Error", () => {
+    expect(() => goBin.matchFilesToModules([duplicatedPath])).toThrow(Error);
+  });
+
+  it("thrown error has a non-empty message containing the file and module names", () => {
+    try {
+      goBin.matchFilesToModules([duplicatedPath]);
+    } catch (err) {
+      expect(err).toBeInstanceOf(GoFileNameError);
+      expect((err as GoFileNameError).message).toBeTruthy();
+      expect((err as GoFileNameError).message).toContain(duplicatedPath);
+      expect((err as GoFileNameError).message).toContain(
+        `${moduleName}@${moduleVersion}`,
+      );
+    }
+  });
+
+  it("thrown error has a stack trace", () => {
+    try {
+      goBin.matchFilesToModules([duplicatedPath]);
+    } catch (err) {
+      expect((err as GoFileNameError).stack).toBeDefined();
+    }
+  });
+
+  it("thrown error carries fileName and moduleName properties", () => {
+    try {
+      goBin.matchFilesToModules([duplicatedPath]);
+    } catch (err) {
+      expect(err).toBeInstanceOf(GoFileNameError);
+      expect((err as GoFileNameError).fileName).toBe(duplicatedPath);
+      expect((err as GoFileNameError).moduleName).toBe(
+        `${moduleName}@${moduleVersion}`,
+      );
+    }
+  });
+
+  it("thrown error has name set to GoFileNameError", () => {
+    try {
+      goBin.matchFilesToModules([duplicatedPath]);
+    } catch (err) {
+      expect((err as GoFileNameError).name).toBe("GoFileNameError");
+    }
+  });
+});