simple_mock - HTTP Mock Server for Eiffel

Overview

simple_mock is an HTTP mock server library for Eiffel that enables testing of HTTP client code without making real network requests. Define expectations, record requests, and verify calls.

Expectation-Based

Define expected requests and the responses to return. Supports status codes, headers, JSON bodies, and delays.

Flexible Matching

Match URLs with glob patterns (* and ?), require specific headers, and validate request bodies.

Request Recording

Track all received requests for verification. Check if URLs were called and how many times.

Fluent API

Chainable configuration methods for building expectations in a readable, declarative style.

Quick Start

local
    l_mock: SIMPLE_MOCK
do
    -- Create mock server
    create l_mock.make

    -- Set up expectation
    l_mock.expect_get ("/api/users")
        .then_respond_json (200, "[{\"id\": 1}]")

    -- Start server
    l_mock.start

    -- Make HTTP calls to http://localhost:8080/api/users

    -- Verify
    if l_mock.was_requested ("/api/users") then
        print ("API called%N")
    end

    l_mock.stop
end

API Reference

SIMPLE_MOCK (Facade)

Feature	Signature	Description
make	make	Create on default port 8080
make_on_port	make_on_port (a_port: INTEGER)	Create on specified port
port	port: INTEGER	Server port number
url	url: STRING	Full URL (http://localhost:port)
is_running	is_running: BOOLEAN	Is server accepting requests?
start	start	Start the mock server
stop	stop	Stop the mock server
reset	reset	Clear all expectations and history
expect	expect (a_method, a_url: STRING): MOCK_EXPECTATION	Create expectation
expect_get	expect_get (a_url: STRING): MOCK_EXPECTATION	Shorthand for GET
expect_post	expect_post (a_url: STRING): MOCK_EXPECTATION	Shorthand for POST
was_requested	was_requested (a_url: STRING): BOOLEAN	Was URL requested?
request_count	request_count (a_url: STRING): INTEGER	Number of requests to URL
verify_all_matched	verify_all_matched: BOOLEAN	All expectations matched?

MOCK_EXPECTATION (Builder Pattern)

Feature	Signature	Description
with_header	with_header (a_name, a_value: STRING): MOCK_EXPECTATION	Require header
with_body	with_body (a_body: STRING): MOCK_EXPECTATION	Require exact body
with_body_containing	with_body_containing (a_text: STRING): MOCK_EXPECTATION	Require body substring
then_respond	then_respond (a_status: INTEGER): MOCK_EXPECTATION	Set response status
then_respond_json	then_respond_json (a_status: INTEGER; a_json: STRING): MOCK_EXPECTATION	Set JSON response
with_response_header	with_response_header (a_name, a_value: STRING): MOCK_EXPECTATION	Add response header
with_delay	with_delay (a_ms: INTEGER): MOCK_EXPECTATION	Add response delay

Examples

Testing an API Client

test_fetch_users
    local
        l_mock: SIMPLE_MOCK
        l_client: MY_API_CLIENT
    do
        -- Setup mock
        create l_mock.make_on_port (9999)
        l_mock.expect_get ("/api/users")
            .with_header ("Authorization", "Bearer token123")
            .then_respond_json (200, "[{\"id\": 1}]")
        l_mock.start

        -- Test client
        create l_client.make ("http://localhost:9999")
        l_client.set_token ("token123")
        l_client.fetch_users

        -- Verify
        assert ("users fetched", l_client.user_count = 1)
        assert ("api called", l_mock.was_requested ("/api/users"))

        l_mock.stop
    end

URL Pattern Matching

-- Exact match
l_mock.expect_get ("/api/users")

-- Wildcard: matches /api/users, /api/posts, etc.
l_mock.expect_get ("/api/*")

-- Single char: matches /api/user1, /api/user2, etc.
l_mock.expect_get ("/api/user?")

-- Path segment: matches /api/123/items, /api/abc/items
l_mock.expect_get ("/api/*/items")

Simulating Delays

-- Simulate slow response (for timeout testing)
l_mock.expect_get ("/api/slow")
    .then_respond (200)
    .with_delay (5000)  -- 5 second delay