From 1ac85ee538b2b27e8f945d7a7733cc21d53fbcb0 Mon Sep 17 00:00:00 2001
From: Yosuke Ota <otameshiyo23@gmail.com>
Date: Wed, 3 May 2023 09:29:00 +0900
Subject: [PATCH] Fix false positives for type def with script setup in ts
 no-unused-vars (#191)

---
 src/script-setup/scope-analyzer.ts                 |  6 ++++++
 .../no-unused-vars/.eslintrc.json                  |  5 +++++
 .../no-unused-vars/valid/type-def.vue              | 14 ++++++++++++++
 3 files changed, 25 insertions(+)
 create mode 100644 test/fixtures/integrations/script-setup-with-typescript-eslint/no-unused-vars/.eslintrc.json
 create mode 100644 test/fixtures/integrations/script-setup-with-typescript-eslint/no-unused-vars/valid/type-def.vue

diff --git a/src/script-setup/scope-analyzer.ts b/src/script-setup/scope-analyzer.ts
index e4f892a..1c078fa 100644
--- a/src/script-setup/scope-analyzer.ts
+++ b/src/script-setup/scope-analyzer.ts
@@ -205,6 +205,12 @@ function analyzeUsedInTemplateVariables(
 
         variable.references.push(reference)
         reference.resolved = variable
+
+        if (reference.isTypeReference) {
+            // @typescript-eslint/no-unused-vars treats type references at the same position as recursive references,
+            // so without this flag it will be marked as unused.
+            ;(variable as any).eslintUsed = true
+        }
     }
 
     function processVExpressionContainer(node: VExpressionContainer) {
diff --git a/test/fixtures/integrations/script-setup-with-typescript-eslint/no-unused-vars/.eslintrc.json b/test/fixtures/integrations/script-setup-with-typescript-eslint/no-unused-vars/.eslintrc.json
new file mode 100644
index 0000000..7592b0b
--- /dev/null
+++ b/test/fixtures/integrations/script-setup-with-typescript-eslint/no-unused-vars/.eslintrc.json
@@ -0,0 +1,5 @@
+{
+    "rules": {
+        "@typescript-eslint/no-unused-vars": "error"
+    }
+}
diff --git a/test/fixtures/integrations/script-setup-with-typescript-eslint/no-unused-vars/valid/type-def.vue b/test/fixtures/integrations/script-setup-with-typescript-eslint/no-unused-vars/valid/type-def.vue
new file mode 100644
index 0000000..ba631bf
--- /dev/null
+++ b/test/fixtures/integrations/script-setup-with-typescript-eslint/no-unused-vars/valid/type-def.vue
@@ -0,0 +1,14 @@
+<script setup lang="ts">
+import MyComponent from "./components/MyComponent.vue";
+interface Foo {
+  foo?: string;
+}
+type Bar = string;
+</script>
+
+<template>
+  <MyComponent
+    :foo="{} as Foo"
+    :bar="'s' as Bar"
+  />
+</template>
\ No newline at end of file