From 801f15c2e8f7a93e469ff0df6b5b08bf74476630 Mon Sep 17 00:00:00 2001
From: Nicolas Morel <nicolas@morel.io>
Date: Sat, 27 Jul 2024 12:07:20 +0200
Subject: [PATCH] fix: coverage for arrow functions returning literals

---
 lib/modules/coverage.js                | 2 +-
 test/coverage.js                       | 5 +++--
 test/coverage/single-line-functions.js | 3 +++
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/lib/modules/coverage.js b/lib/modules/coverage.js
index 6fe2e1ef..60c323bb 100755
--- a/lib/modules/coverage.js
+++ b/lib/modules/coverage.js
@@ -307,7 +307,7 @@ internals.instrument = function (filename, ctx) {
             node.set(`(global.__$$labCov._statement(\'${filename}\',${left},${line},${node.left.source()})${node.operator}global.__$$labCov._statement(\'${filename}\',${right},${line},${node.right.source()}))`);
         }
         else if (node.parent?.type === 'ArrowFunctionExpression' &&
-            node.type.includes('Expression')) {
+            (node.type.includes('Expression') || node.type === 'Literal')) {
 
             const id = addStatement(line, node, false);
 
diff --git a/test/coverage.js b/test/coverage.js
index f2635ff5..2cf34aab 100755
--- a/test/coverage.js
+++ b/test/coverage.js
@@ -484,12 +484,13 @@ describe('Coverage', () => {
         results.push(Test.method11(5, 10));
         results.push(Test.method11(0, 10));
         results.push(Test.method11Partial(5, 10));
+        results.push(Test.method12());
 
         const cov = await Lab.coverage.analyze({ coveragePath: Path.join(__dirname, 'coverage/single-line-functions') });
         const source = cov.files[0].source;
         const missedLines = Object.keys(source).filter((lineNumber) => source[lineNumber].miss);
-        expect(results).to.equal([7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 5, 10, 5]);
-        expect(missedLines).to.equal(['12', '15', '21', '27', '30', '33', '39', '46', '50', '53', '56']);
+        expect(results).to.equal([7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 5, 10, 5, 42]);
+        expect(missedLines).to.equal(['12', '15', '21', '27', '30', '33', '39', '46', '50', '53', '56', '59']);
     });
 
     it('should measure missing coverage on trailing function declarations correctly', async () => {
diff --git a/test/coverage/single-line-functions.js b/test/coverage/single-line-functions.js
index 103cd905..f00c1683 100644
--- a/test/coverage/single-line-functions.js
+++ b/test/coverage/single-line-functions.js
@@ -54,3 +54,6 @@ exports.method10NotCalled = (a, b) => exports.method9NotCalled(a, b);
 
 exports.method11 = (a, b) => a || b;
 exports.method11Partial = (a, b) => a || b;
+
+exports.method12 = () => 42;
+exports.method12NotCalled = () => 42;