test(ai-proxy): expand wasm integration tests, coverage, and provider matrix (#3790)

Signed-off-by: jingze <daijingze.djz@alibaba-inc.com>

plugins/wasm-go/extensions/ai-proxy/util/header_slice_test.go

@@ -0,0 +1,39 @@
+package util
+
+import (
+	"net/http"
+	"reflect"
+	"testing"
+)
+
+func TestCreateHeaders(t *testing.T) {
+	h := CreateHeaders("Content-Type", "application/json", ":status", "200")
+	if len(h) != 2 {
+		t.Fatalf("len=%d", len(h))
+	}
+	if h[0][0] != "Content-Type" || h[0][1] != "application/json" {
+		t.Fatalf("first pair: %v", h[0])
+	}
+}
+
+func TestHeaderToSliceAndSliceToHeader_roundTrip(t *testing.T) {
+	src := make(http.Header)
+	src.Set("A", "1")
+	src.Add("A", "2")
+	src.Set("B", "3")
+
+	slice := HeaderToSlice(src)
+	round := SliceToHeader(slice)
+
+	if !reflect.DeepEqual(src["A"], round["A"]) || !reflect.DeepEqual(src["B"], round["B"]) {
+		t.Fatalf("roundTrip mismatch: %#v vs %#v", src, round)
+	}
+}
+
+func TestOverwriteRequestPathHeader(t *testing.T) {
+	h := make(http.Header)
+	OverwriteRequestPathHeader(h, "/v1/chat/completions")
+	if h.Get(":path") != "/v1/chat/completions" {
+		t.Fatalf("path=%q", h.Get(":path"))
+	}
+}