fix: throw "lcov is empty" instead of "parsing error!"

index.js

@@ -1,14 +1,19 @@
 const core = require('@actions/core');
 const minimatch = require('minimatch');
 const parse = require('lcov-parse');
+const fs = require('fs');
 
 function run() {
   const lcovPath = core.getInput('path');
   const minCoverage = core.getInput('min_coverage');
   const excluded = core.getInput('exclude');
   const excludedFiles = excluded.split(' ');
 
-  parse(lcovPath, (_, data) => {
+  if (!canParse(lcovPath)) {
+    return;
+  }
+
+  parse(lcovPath, (err, data) => {
     if (typeof data === 'undefined') {
       core.setFailed('parsing error!');
       return;
@@ -65,4 +70,13 @@ function shouldCalculateCoverageForFile(fileName, excludedFiles) {
   return true;
 }
 
+function canParse(path) {
+  if (fs.existsSync(path) && fs.readFileSync(path).length === 0) {
+    core.setFailed('lcov is empty!');
+    return false;
+  }
+
+  return true;
+}
+
 run();

index.test.js

@@ -12,6 +12,21 @@ const getErrorOutput = (error) => {
   return output;
 };
 
+test('empty LCOV throws an error', () => {
+  const lcovPath = './fixtures/lcov.empty.info';
+  process.env['INPUT_PATH'] = lcovPath;
+  const ip = path.join(__dirname, 'index.js');
+  try {
+    cp.execSync(`node ${ip}`, { env: process.env });
+    fail('this code should fail');
+  } catch (err) {
+    expect(err).toBeDefined();
+
+    const errorMessage = err.stdout.toString();
+    expect(errorMessage).toContain('lcov is empty!');
+  }
+});
+
 test('invalid LCOV format throws an error', () => {
   const lcovPath = './fixtures/lcov.error.info';
   process.env['INPUT_PATH'] = lcovPath;
@@ -21,6 +36,9 @@ test('invalid LCOV format throws an error', () => {
     fail('this code should fail');
   } catch (err) {
     expect(err).toBeDefined();
+
+    const errorMessage = err.stdout.toString();
+    expect(errorMessage).toContain('parsing error!');
   }
 });