mheiber

Are Mocks a Smell?

It's hard to write unit tests that are worth the costs our employers pay for them. I'll share two mostly-made-up diagrams then use them to justify writing code as data transformation.

Factual Diagrams

There are four types of code:

**Diagram 1: Types of Code**

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// Test for Architecture 2

assert.deepEqual(
    buildRequest(x, y, z),
    expectedRequest
)

assert.deepEqual(
    parseResponse(response),
    expectedParsedResponse

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// Test for Architecture 1

fetch = spy().andMockWith(function (args) {
    // pattern matching and pretend games
})
assertSpyStuff
assertMoreSpyStuff
assertMoreSpyStuff

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**Diagram 2: Should I unit test?**

                       high
                       ^                ||
                       ^                ||
                       ^  don't test    ||  maybe test
                       ^                ||
cost of testing        ^ ================================
 ^ ||

mheiber

**Diagram 1: Types of Code**

                       high
                       ^                ||
                       ^                ||
                       ^ boring I/O     ||  interesting I/O
                       ^                ||
cost of testing        ^ ================================
 ^ ||

mheiber

// Architecture 2

function callApi(x, y, z) {
    const request = buildRequest(x, y, z)
    return fetch(request)
            .then(assertStatus('callApi', x, y, z))
            .then(parseResponse)

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// Architecture 1

function callApi(x, y, z) {
    manipulate params
    manipulate params some more ...
    return fetch(...)
        .then(result => {
            if (result.status === ...) {
                handle status stuff
            }

mheiber

#!/bin/bash
# written with @felkerch
REPO=$1
VERSION=$2
cd ../$REPO
git fetch
git checkout v$VERSION
npm link
cd -
npm link $REPO 

mheiber

#!/bin/bash
REPO=$1
VERSION=$2
cd ../$REPO
git fetch
git checkout v$VERSION
npm link
cd -
npm link $REPO 

mheiber

<style lang="sass">

</style>

<template>
  <input
    class="input-text"
    @input="update"
    :placeholder="args.placeholder"
    :value="value"