Function TestStableRequestEncoding

internal/integrationtest/bridge_test.go:1401–1462

TestStableRequestEncoding validates that a given intercepted request and a given set of injected tools should result identical payloads. Should the payload vary, it may subvert any caching mechanisms the provider may have.

(t *testing.T)

//
// Should the payload vary, it may subvert any caching mechanisms the provider may have.
func TestStableRequestEncoding(t *testing.T) {
	t.Parallel()

	cases := []struct {
		name    string
		fixture []byte
		path    string
	}{
		{
			name:    config.ProviderAnthropic,
			fixture: fixtures.AntSimple,
			path:    pathAnthropicMessages,
		},
		{
			name:    config.ProviderOpenAI,
			fixture: fixtures.OaiChatSimple,
			path:    pathOpenAIChatCompletions,
		},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()

			ctx, cancel := context.WithTimeout(t.Context(), testutil.WaitLong)
			t.Cleanup(cancel)

			// Setup MCP tools.
			mockMCP := setupMCPForTest(t, defaultTracer)

			fix := fixtures.Parse(t, tc.fixture)

			// Create a mock upstream that serves the same blocking response for each request.
			count := 10
			responses := make([]upstreamResponse, count)
			for i := range count {
				responses[i] = newFixtureResponse(fix)
			}
			upstream := newMockUpstream(ctx, t, responses...)

			bridgeServer := newBridgeTestServer(ctx, t, upstream.URL,
				withMCP(mockMCP),
			)

			// Make multiple requests and verify they all have identical payloads.
			for range count {
				resp, err := bridgeServer.makeRequest(t, http.MethodPost, tc.path, fix.Request())
				require.NoError(t, err)
				defer resp.Body.Close()
				require.Equal(t, http.StatusOK, resp.StatusCode)
			}

			// All upstream request bodies should be identical.
			received := upstream.receivedRequests()
			require.Len(t, received, count)
			reference := string(received[0].Body)
			for _, r := range received[1:] {
				assert.JSONEq(t, reference, string(r.Body))