"io" Test Utilities

Configurable mock/test implementations of commonly used io package interfaces.

io.Reader | io.ReadCloser

Using iotest.ReadCloser you can mock an instance of io.Reader or io.ReadCloser (or just io.Closer if you wanted).

The mock/test struct allows you to configure when/if errors are returned, what "written byte" counts are returned, and the contents of the source to read from. Additionally, the struct will contain a count of calls to Read and Close.

Basic Usage

package main

import (
  "fmt"

  "github.com/vulpine-io/io-test/v1/pkg/iotest"
)

func main() {
  reader := new(iotest.ReadCloser)
  buffer := make([]byte, 10)

  fmt.Println(reader.Read(buffer)) // 10 <nil>
  fmt.Println(string(buffer))      // abcdefghij
  fmt.Println(reader.ReadCalls)    // 1
}

io.Writer | io.WriteCloser

Using iotest.WriteCloser you can mock an instance of io.Writer or io.WriteCloser (or just io.Closer if you wanted).

The mock/test struct allows you to configure when/if errors are returned and what "written byte" counts are returned. Additionally, the struct will contain a count of calls to Write and Close in addition to a slice of all the data passed to the Write method.

Basic Usage

package main

import (
  "fmt"

  "github.com/vulpine-io/io-test/v1/pkg/iotest"
)

func main() {
  writer := new(iotest.WriteCloser)
  data := []byte("hey there!")

  fmt.Println(writer.Write(data))          // 10 <nil>
  fmt.Println(string(writer.WrittenBytes)) // hey there!
  fmt.Println(writer.WriteCalls)           // 1
}

Planned

• io.ByteScanner

• io.RuneScanner

• io.ByteReader

• io.RuneReader