How do I test Fiber handlers without app.Test?

Record the running binary with Keploy. Because capture is at the socket below fasthttp, the app from main serves the request — so route registration, middleware order, and BodyParser are all genuinely exercised.

Does Fiber middleware run under Keploy?

Yes. The request arrives over a real socket, so recover, logger, CORS, and JWT all execute in the order main registers them, and the recorded case replays that path.

Does Keploy work with fasthttp?

Yes. Capture happens below the HTTP server rather than inside net/http, so Fiber's fasthttp foundation makes no difference to what is recorded or replayed.

Can Keploy replace go-sqlmock in Fiber projects?

Yes, for integration tests. sqlmock asserts on the SQL string your code emits, so every query is written twice. Keploy records the protocol beneath database/sql and captures the real rows.

Is Keploy free for Fiber projects?

Yes. The Keploy CLI is open source under Apache 2.0 and free to run on any Go service with no seat limits. It is not a Go module, so it never appears in go.mod.

Keploy as a Fiber testing framework

Keploy tests Fiber applications by recording real requests through the running server and every SQL or outbound call they trigger, then replaying both as assertions. The fasthttp handler chain runs in full, because the request arrived over a real socket.

Generate Fiber tests free

keploy record -c "./orders-api"

18.4K+

1.2M+300M+mocks createdSlack

What Keploy gives a Fiber team

Any Fiber app, unchanged

Keploy runs the binary you build. Fiber sits on fasthttp rather than net/http, and capture happens below both — so the router, groups, and middleware all execute unchanged.

Fiber v2 and above
Route groups and nested middleware
fasthttp handler chain
No test-only fiber.New()

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The problem

Why Fiber integration tests slow teams down

The friction is rarely the assertions. It is everything around them — spinning up dependencies, keeping mocks honest, and repairing tests after every refactor.

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Three ways to do it

Testing Fiber: by hand, with testify + httptest, or with Keploy

app.Test drives an app the test file assembled, so middleware from main is missing. Keploy records the running binary, so the server under test is the one you deploy.

By hand

testify + httptest

With Keploy

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Same coverage, three costs

What you write for Fiber vs what Keploy records

All three produce the same assertion. Only the third still passes after the next refactor without anyone editing it.

By hand2–4 hours

handler_manual_test.go

hand-written

// Hand-written: an app assembled here, not in main.

package api

func TestConfirmOrder(t *testing.T) {

app := fiber.New()

// Note what is missing: recover, logger, and JWT from main.

app.Post("/orders/:id/confirm", NewHandler(fakeRepo{}, fakePayments{}).Confirm)

body := strings.NewReader(`{"paymentToken":"tok_123"}`)

req := httptest.NewRequest("POST", "/orders/ord_1/confirm", body)

req.Header.Set("Content-Type", "application/json")

res, err := app.Test(req)

if err != nil || res.StatusCode != 200 {

t.Fatalf("got %v status %d", err, res.StatusCode)

}

The app is built here, so an unauthorised request passes: the JWT middleware main registers is not part of this chain.

testify + httptest1–2 hours

handler_sqlmock_test.go

tool-assisted

// testify + sqlmock + an httptest stub upstream.

package api

func TestConfirmOrder(t *testing.T) {

db, mock, _ := sqlmock.New()

defer db.Close()

// The query now lives in two places.

mock.ExpectQuery("SELECT id, amount_minor, state FROM orders").

WithArgs("ord_1").

WillReturnRows(sqlmock.NewRows([]string{"id", "amount_minor", "state"}).

AddRow("ord_1", 4200, "NEW"))

upstream := httptest.NewServer(stripeStub())

defer upstream.Close()

res := serve(t, NewRepo(db), NewPayments(upstream.URL))

assert.Equal(t, 200, res.StatusCode)

assert.NoError(t, mock.ExpectationsWereMet())

}

Fast and idiomatic — and the SQL is duplicated while stripeStub() is a handler someone keeps current by hand.

With Keploy~5 minutes

test-1.yaml

auto-generated

# Recorded with: keploy record -c './orders-api'

# Nobody wrote this file. Keploy captured it from a real request.

version: api.keploy.io/v1beta1

kind: Http

name: test-1

spec:

req:

method: POST

url: /orders/ord_1/confirm

header:

Authorization: Bearer <captured>

body: '{"paymentToken":"tok_123"}'

resp:

status_code: 200

body:

id: "ord_1"

state: "CONFIRMED"

amountMinor: 4200

noise:

- body.confirmedAt

mocks:

- kind: Postgres

operation: "SELECT id, amount_minor, state FROM orders WHERE id = $1"

- kind: Http

url: https://api.payments.example.com/v1/payment_intents/tok_123/confirm

The recorded case travelled the real fasthttp chain from main, so the JWT check and BodyParser both ran before the handler saw it.

Times are estimates for authoring one endpoint’s coverage from scratch, not measurements.

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Keploy vs the alternatives

Fiber testing tools, compared

The options a team on Go actually reaches for, and where each one genuinely wins. Select a row for the full comparison.

Keploy

testify + httptest

go-sqlmock

GoMock

Testcontainers

Postman

SmartBear ReadyAPI

Best in classStrongPartialNot covered

Assessments reflect each tool’s documented behaviour, not benchmark measurements.

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How it works

Record your Fiber app once, replay it forever

Keploy sits below your Fiber process at the network layer. It watches the calls your app already makes, then serves them back on replay so tests run with no dependencies attached.

Your Fiber appGET/api/v1/orders/{id}200

RecordingKeploy proxyeBPF · userspace

PostgreSQLPostgres frontend/backend protocol

MySQLMySQL wire protocol

MongoDBMongoDB wire protocol

RedisRESP over TCP

+3 more Fiber dependencies

An example shape of a captured call. Your own endpoints and dependencies come from your real traffic, so nothing here has to be written by hand.

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Mock coverage

What Keploy mocks for Fiber, with zero config

7 of the 7 dependencies a typical Fiber service talks to are stubbed from the recording itself — no mock classes, no fixture files, no containers in CI.

Auto-mocked
PostgreSQLView page
Postgres frontend/backend protocol
Auto-mocked
MySQLView page
MySQL wire protocol
Auto-mocked
MongoDBView page
MongoDB wire protocol
Auto-mocked
RedisView page
RESP over TCP
Auto-mocked
Apache KafkaView page
Kafka producer and consumer protocol
Auto-mocked
gRPCView page
HTTP/2 framed gRPC calls
Outbound HTTP
Auto-mocked
Outbound HTTP
Any HTTP client call the service makes

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Quick start

Your first Fiber test suite in under five minutes

Every command below runs against your existing Fiber service. Nothing in your source tree changes.

1
1Install the Keploy CLI
A single binary. It needs a Linux kernel with eBPF support, or Docker on macOS and Windows — and it adds nothing to your project's dependencies.
curl -sSL https://keploy.io/install.sh | bash
2
2Record your service
Pass the command you already use to start the app. Keploy runs it and watches every socket it opens.
keploy record -c "./orders-api"
3
3Exercise the paths you care about
Drive the running server. Every request becomes a test case with its database and HTTP calls captured alongside.
go build -o orders-api ./cmd/api
curl -X POST localhost:8080/orders/ord_1/confirm -H 'Content-Type: application/json' -H 'Authorization: Bearer $TOKEN' -d '{"paymentToken":"tok_123"}'
4
4Replay in CI
Replay serves the recorded dependency responses, so the job needs no service containers and no Docker daemon.
keploy test -c "./orders-api" --delay 6