CtrlK
BlogDocsLog inGet started
Tessl Logo

testland/grpc-interceptor-test-author

Authors unit tests for gRPC interceptor logic: Go grpc.UnaryServerInterceptor/UnaryClientInterceptor, Java ServerInterceptor/ClientInterceptor, and grpc-js client interceptors. Covers auth (Unauthenticated on bad token), retry (backoff on Unavailable), logging/tracing (metadata extraction + propagation), error-mapping (status translation), and chained interceptor ordering - by calling the interceptor directly with a spy handler, no live backend. Use when a gRPC interceptor is written or modified. Different test surface from grpc-streaming-test-author (multi-message stream sequences) and grpc-mock (service handler logic) - use those, not this, for streams or handlers.

74

Quality

93%

Does it follow best practices?

Run evals on this skill

Adds up to 20 points to the overall score

View guide

SecuritybySnyk

Passed

No findings from the security scan

Overview
Quality
Evals
Security
Files

grpc-js-interceptors.mdreferences/

grpc-js client interceptor tests

@grpc/grpc-js exposes client interceptors as a channel option. The package README confirms "Client Interceptors" as a supported feature at github.com/grpc/grpc-node/tree/master/packages/grpc-js. An interceptor is a function (options, nextCall) => InterceptingCall.

Client interceptor - auth-header injection

Test an auth-header injector by building an InterceptingCall with a RequesterBuilder that captures the outbound metadata:

import * as grpc from "@grpc/grpc-js";
import { InterceptingCall, InterceptorOptions, NextCall } from "@grpc/grpc-js";

function authInterceptor(token: string) {
    return (options: InterceptorOptions, nextCall: NextCall): InterceptingCall => {
        return new InterceptingCall(nextCall(options), {
            start(metadata, listener, next) {
                metadata.add("authorization", `Bearer ${token}`);
                next(metadata, listener);
            },
        });
    };
}

// Test using a spy on the nextCall layer
test("authInterceptor injects Authorization header", () => {
    let capturedMetadata: grpc.Metadata | undefined;

    const fakeNext: NextCall = (_options) =>
        new InterceptingCall(null as any, {
            start(metadata, _listener, _next) {
                capturedMetadata = metadata;
            },
        });

    const interceptorFn = authInterceptor("my-token");
    const call = interceptorFn({} as InterceptorOptions, fakeNext);
    call.start(new grpc.Metadata(), {} as grpc.Listener);

    expect(capturedMetadata?.get("authorization")).toEqual(["Bearer my-token"]);
});

Register on a channel:

const client = new UserServiceClient(address, credentials, {
    interceptors: [authInterceptor("my-token")],
});

references

go-interceptors.md

grpc-js-interceptors.md

java-interceptors.md

SKILL.md

tile.json