From 49399276f4cb9c8aaf98d82d06eecb31430e906d Mon Sep 17 00:00:00 2001
From: msyyc <70930885+msyyc@users.noreply.github.com>
Date: Thu, 8 Aug 2024 15:18:45 +0800
Subject: [PATCH 1/2] fic collectionFormat for csv

---
 .../typespec-client-generator-core/src/http.ts |  6 +-----
 .../test/package.test.ts                       | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/packages/typespec-client-generator-core/src/http.ts b/packages/typespec-client-generator-core/src/http.ts
index 476118455e..81b3cb6d3a 100644
--- a/packages/typespec-client-generator-core/src/http.ts
+++ b/packages/typespec-client-generator-core/src/http.ts
@@ -596,11 +596,7 @@ function getCollectionFormat(
         ? getHeaderFieldOptions(program, type)
         : undefined
   )?.format;
-  if (
-    tspCollectionFormat === "form" ||
-    tspCollectionFormat === "simple" ||
-    tspCollectionFormat === "csv"
-  ) {
+  if (tspCollectionFormat === "form" || tspCollectionFormat === "simple") {
     return undefined;
   }
   return tspCollectionFormat;
diff --git a/packages/typespec-client-generator-core/test/package.test.ts b/packages/typespec-client-generator-core/test/package.test.ts
index a42f827856..132e612b85 100644
--- a/packages/typespec-client-generator-core/test/package.test.ts
+++ b/packages/typespec-client-generator-core/test/package.test.ts
@@ -1251,6 +1251,24 @@ describe("typespec-client-generator-core: package", () => {
       strictEqual(queryParm.collectionFormat, "multi");
     });
 
+    it("query collection format for csv", async () => {
+      await runner.compile(`@server("http://localhost:3000", "endpoint")
+      @service({})
+      namespace My.Service;
+      
+      #suppress "deprecated" "Legacy test"
+      op myOp(@query({format: "csv"}) query: string): void;
+      `);
+      const sdkPackage = runner.context.sdkPackage;
+      const method = getServiceMethodOfClient(sdkPackage);
+      strictEqual(method.kind, "basic");
+
+      strictEqual(method.operation.parameters.length, 1);
+      const queryParm = method.operation.parameters[0];
+      strictEqual(queryParm.kind, "query");
+      strictEqual(queryParm.collectionFormat, "csv");
+    });
+
     it("body basic", async () => {
       await runner.compile(`@server("http://localhost:3000", "endpoint")
         @service({})

From 87b67a6d2d73f0b51fd3cc05ed9a76a88cb4d007 Mon Sep 17 00:00:00 2001
From: msyyc <70930885+msyyc@users.noreply.github.com>
Date: Thu, 8 Aug 2024 15:19:34 +0800
Subject: [PATCH 2/2] changelog

---
 .../changes/tcgc-fix-uri-template-2024-7-8-15-19-24.md     | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 .chronus/changes/tcgc-fix-uri-template-2024-7-8-15-19-24.md

diff --git a/.chronus/changes/tcgc-fix-uri-template-2024-7-8-15-19-24.md b/.chronus/changes/tcgc-fix-uri-template-2024-7-8-15-19-24.md
new file mode 100644
index 0000000000..7578436da7
--- /dev/null
+++ b/.chronus/changes/tcgc-fix-uri-template-2024-7-8-15-19-24.md
@@ -0,0 +1,7 @@
+---
+changeKind: fix
+packages:
+  - "@azure-tools/typespec-client-generator-core"
+---
+
+Fix collectionFormat for "csv"
\ No newline at end of file