mock: interface-only

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Exhibit path: docs/examples/codegen/mock/interface-only/

A single interface with two methods, annotated with +glacier:mock. The minimal working case for the mock generator.

Input (in.go)

//go:build glacier_codegen_fixture

// Package store defines the data-access interface for the application.
package store

import "context"

// Store is the data-access interface.
//
// +glacier:mock
type Store interface {
	// Get retrieves a record by ID.
	Get(ctx context.Context, id string) (string, error)

	// Put writes a record by ID.
	Put(ctx context.Context, id string, value string) error
}

Output (out.go)

//go:build glacier_codegen_fixture

// Code generated by glaciergen. DO NOT EDIT.
// Source: in.go
package store

import "context"

// MockStore is a generated mock for Store.
type MockStore struct {
	// OnGet is called by Get. Set this in your test to control behavior.
	OnGet func(ctx context.Context, id string) (string, error)

	// OnPut is called by Put. Set this in your test to control behavior.
	OnPut func(ctx context.Context, id string, value string) error
}

// Get implements Store.
func (m *MockStore) Get(ctx context.Context, id string) (string, error) {
	return m.OnGet(ctx, id)
}

// Put implements Store.
func (m *MockStore) Put(ctx context.Context, id string, value string) error {
	return m.OnPut(ctx, id, value)
}

What the generator did

• Found the +glacier:mock marker on the Store interface.
• Generated a MockStore struct that implements Store.
• Each method has a corresponding OnXxx recorder field that test code populates with expected call behavior.
• The mock is typed at compile time: no interface{} parameters or return values appear in the generated code.

Related

nested-interfaces with-types-from-other-package glacier generate