From e0308f1c885a8f7972d3f632e563dd918d68e9df Mon Sep 17 00:00:00 2001
From: Vladimir <sleuths.slews0s@icloud.com>
Date: Tue, 17 Dec 2024 10:20:38 +0100
Subject: [PATCH] fix: reset istanbul coverage between runs (#560)

---
 src/api.ts           |  4 ++++
 src/api/rpc.ts       |  1 +
 src/runner/runner.ts | 10 ++++++++++
 src/worker/vitest.ts | 17 +++++++++++++++++
 4 files changed, 32 insertions(+)

diff --git a/src/api.ts b/src/api.ts
index 1513670..2fddef5 100644
--- a/src/api.ts
+++ b/src/api.ts
@@ -194,6 +194,10 @@ export class VitestFolderAPI {
     return this.meta.rpc.waitForCoverageReport()
   }
 
+  async invalidateIstanbulTestModules(modules: string[] | null) {
+    await this.meta.rpc.invalidateIstanbulTestModules(modules)
+  }
+
   async enableCoverage() {
     await this.meta.rpc.enableCoverage()
   }
diff --git a/src/api/rpc.ts b/src/api/rpc.ts
index 194ad1b..e2bdac7 100644
--- a/src/api/rpc.ts
+++ b/src/api/rpc.ts
@@ -18,6 +18,7 @@ export interface VitestMethods {
   watchTests: (files?: SerializedTestSpecification[] | string[], testNamePattern?: string) => void
   unwatchTests: () => void
 
+  invalidateIstanbulTestModules: (modules: string[] | null) => Promise<void>
   enableCoverage: () => void
   disableCoverage: () => void
   waitForCoverageReport: () => Promise<string | null>
diff --git a/src/runner/runner.ts b/src/runner/runner.ts
index 6dbbe3c..655124a 100644
--- a/src/runner/runner.ts
+++ b/src/runner/runner.ts
@@ -222,6 +222,16 @@ export class TestRunner extends vscode.Disposable {
       }),
     )
 
+    const modules = !request.include
+      ? null
+      : getTestFiles(request.include).map((f) => {
+        if (typeof f === 'string') {
+          return f
+        }
+        return f[1]
+      })
+
+    await this.api.invalidateIstanbulTestModules(modules)
     await this.runTests(request, token)
   }
 
diff --git a/src/worker/vitest.ts b/src/worker/vitest.ts
index 0894b3f..3630284 100644
--- a/src/worker/vitest.ts
+++ b/src/worker/vitest.ts
@@ -301,6 +301,23 @@ export class Vitest implements VitestMethods {
       this.watcher.trackEveryFile()
   }
 
+  // we need to invalidate the modules because Vitest caches the code injected by istanbul
+  async invalidateIstanbulTestModules(modules: string[] | null) {
+    if (!this.coverage.enabled || this.coverage.config.provider !== 'istanbul') {
+      return
+    }
+    if (!modules) {
+      this.ctx.server.moduleGraph.invalidateAll()
+      return
+    }
+    modules.forEach((moduleId) => {
+      const mod = this.ctx.server.moduleGraph.getModuleById(moduleId)
+      if (mod) {
+        this.invalidateTree(mod)
+      }
+    })
+  }
+
   disableCoverage() {
     return this.coverage.disable()
   }
-- 
2.51.2