fix: add check+test for gcov installed

Author: michael-codecov

src/helpers/gcov.ts

@@ -1,7 +1,11 @@
 import glob from 'fast-glob'
-import { runExternalProgram } from "./util"
+import { isProgramInstalled, runExternalProgram } from "./util"
 
 export function generateGcovCoverageFiles(projectRoot: string, include: string[] = [], ignore: string[] = [], gcovArgs = '',) {
+    if (!isProgramInstalled('gcov')) {
+        throw new Error('gcov is not installed, cannot process files')
+    }
+
     const globstar = (pattern: string) => `**/${pattern}`
     const gcovInclude = ['*.gcno', ...include].map(globstar)
     const gcovIgnore = ['bower_components', 'node_modules', 'vendor', ...ignore].map(globstar)

test/helpers/gcov.test.ts

@@ -6,7 +6,7 @@ import { generateGcovCoverageFiles } from '../../src/helpers/gcov'
 describe('generateGcovCoverageFiles()', () => {
     afterEach(() => {
         td.reset()
-      })
+    })
 
     it('should find and run on test/fixtures/gcov/main.gcno', () => {
         const projectRoot = process.cwd()
@@ -21,18 +21,30 @@ Lines executed:0.00% of 11`)
     })
     it('should find no gcno files and return an error', () => {
         const projectRoot = process.cwd()
-        expect(() => {generateGcovCoverageFiles(projectRoot, [], ['test'])}).toThrowError(/No gcov files found/)
+        expect(() => { generateGcovCoverageFiles(projectRoot, [], ['test']) }).toThrowError(/No gcov files found/)
 
 
     })
 
     it('should pass gcov arguments directly through', () => {
         const spawnSync = td.replace(childProcess, 'spawnSync')
+        td.when(spawnSync('gcov')).thenReturn({
+            stdout: 'gcov installed',
+            error: null
+        })
         td.when(spawnSync('gcov', td.matchers.contains('NEWGCOVARG'))).thenReturn({
-          stdout: 'Matched',
+            stdout: 'Matched',
         })
 
         const projectRoot = process.cwd()
-        expect(generateGcovCoverageFiles(projectRoot,[],[],'NEWGCOVARG')).toEqual("Matched")
+        expect(generateGcovCoverageFiles(projectRoot, [], [], 'NEWGCOVARG')).toEqual("Matched")
+    })
+
+    it('should return an error when gcov is not installed', () => {
+        const spawnSync = td.replace(childProcess, 'spawnSync')
+        td.when(spawnSync('gcov')).thenReturn({ error: "Command 'gcov' not found" })
+
+        const projectRoot = process.cwd()
+        expect(() => generateGcovCoverageFiles(projectRoot, [], [], 'NEWGCOVARG')).toThrowError(/gcov is not installed/)
     })
 })