From fef8aa470d1fe4978a7fa7f3b15e1f87a48af7be Mon Sep 17 00:00:00 2001
From: AriPerkkio <ari.perkkio@gmail.com>
Date: Mon, 12 Dec 2022 20:30:06 +0200
Subject: [PATCH] fix(coverage): esbuild to preserve legal comments for ignore
 hints

---
 packages/vitest/src/node/plugins/index.ts     |   3 +
 .../__snapshots__/c8.report.test.ts.snap      | 105 ++++++++++++++++++
 test/coverage-test/src/utils.ts               |   5 +
 3 files changed, 113 insertions(+)

diff --git a/packages/vitest/src/node/plugins/index.ts b/packages/vitest/src/node/plugins/index.ts
index 26c1e51c73f3..839f460935f5 100644
--- a/packages/vitest/src/node/plugins/index.ts
+++ b/packages/vitest/src/node/plugins/index.ts
@@ -92,6 +92,9 @@ export async function VitestPlugin(options: UserConfig = {}, ctx = new Vitest('t
         const config: ViteConfig = {
           esbuild: {
             sourcemap: 'external',
+
+            // Enables using ignore hint for coverage providers with @preserve keyword
+            legalComments: 'inline',
           },
           resolve: {
             // by default Vite resolves `module` field, which not always a native ESM module
diff --git a/test/coverage-test/coverage-report-tests/__snapshots__/c8.report.test.ts.snap b/test/coverage-test/coverage-report-tests/__snapshots__/c8.report.test.ts.snap
index f176dbf905c3..f4bc12646001 100644
--- a/test/coverage-test/coverage-report-tests/__snapshots__/c8.report.test.ts.snap
+++ b/test/coverage-test/coverage-report-tests/__snapshots__/c8.report.test.ts.snap
@@ -2272,6 +2272,8 @@ exports[`c8 json report 1`] = `
     "f": {
       "0": 1,
       "1": 1,
+      "10": 0,
+      "11": 0,
       "2": 2,
       "3": 2,
       "4": 0,
@@ -2330,6 +2332,54 @@ exports[`c8 json report 1`] = `
         },
         "name": "get",
       },
+      "10": {
+        "decl": {
+          "end": {
+            "column": 1,
+            "line": 29,
+          },
+          "start": {
+            "column": 7,
+            "line": 27,
+          },
+        },
+        "line": 27,
+        "loc": {
+          "end": {
+            "column": 1,
+            "line": 29,
+          },
+          "start": {
+            "column": 7,
+            "line": 27,
+          },
+        },
+        "name": "unusedFunction",
+      },
+      "11": {
+        "decl": {
+          "end": {
+            "column": 1,
+            "line": 29,
+          },
+          "start": {
+            "column": 0,
+            "line": 29,
+          },
+        },
+        "line": 29,
+        "loc": {
+          "end": {
+            "column": 1,
+            "line": 29,
+          },
+          "start": {
+            "column": 0,
+            "line": 29,
+          },
+        },
+        "name": "get",
+      },
       "2": {
         "decl": {
           "end": {
@@ -2542,6 +2592,11 @@ exports[`c8 json report 1`] = `
       "21": 0,
       "22": 0,
       "23": 0,
+      "24": 1,
+      "25": 1,
+      "26": 1,
+      "27": 0,
+      "28": 0,
       "3": 1,
       "4": 1,
       "5": 2,
@@ -2721,6 +2776,56 @@ exports[`c8 json report 1`] = `
           "line": 24,
         },
       },
+      "24": {
+        "end": {
+          "column": 0,
+          "line": 25,
+        },
+        "start": {
+          "column": 0,
+          "line": 25,
+        },
+      },
+      "25": {
+        "end": {
+          "column": 39,
+          "line": 26,
+        },
+        "start": {
+          "column": 0,
+          "line": 26,
+        },
+      },
+      "26": {
+        "end": {
+          "column": 34,
+          "line": 27,
+        },
+        "start": {
+          "column": 0,
+          "line": 27,
+        },
+      },
+      "27": {
+        "end": {
+          "column": 73,
+          "line": 28,
+        },
+        "start": {
+          "column": 0,
+          "line": 28,
+        },
+      },
+      "28": {
+        "end": {
+          "column": 1,
+          "line": 29,
+        },
+        "start": {
+          "column": 0,
+          "line": 29,
+        },
+      },
       "3": {
         "end": {
           "column": 0,
diff --git a/test/coverage-test/src/utils.ts b/test/coverage-test/src/utils.ts
index 3b2ffc2048a4..b61751a451d9 100644
--- a/test/coverage-test/src/utils.ts
+++ b/test/coverage-test/src/utils.ts
@@ -22,3 +22,8 @@ export function run() {
   // this should not be covered
   divide(1, 1)
 }
+
+/* istanbul ignore next -- @preserve */
+export function unusedFunction() {
+  return 'This function is not used, but excluded from istanbul coverage'
+}