Intro to BDD Syntax

Kyle Coberly

kylecoberly.com

  • Educator
  • Business Dork
  • Software Developer

Learning Objective:

Recall the 3 types of Chai particles

Test-First Development

TDD vs. BDD

assert.equal(sum(1, 1), 2)
expect(sum(1, 1)).to.equal(2)

System's Perspective

User's Perspective

What mindset does writing the test put you in?

Can non-technical people understand your assertions?

Chai

  • Assertion Library
  • Syntax for assert, expect, and should
  • Works with any test runner

expect Particles
  • Chainers
  • Assertions
  • Flags 
const people = [{
	kyle: { name: "Kyle", height: 90 },
	dusing: { name: "Dusing", height: 100 },
}]
const tallestPerson = { name: "Dusing", height: 100 }

expect(getTallest(people)).to.deep.equal(tallestPerson)

Chainer

Assertion

Flag

Chainers

  • to, be
  • have, has
  • a, an
  • and, but

Assertions

  • equal
  • property
  • a, an
  • true, false, ok, exist
  • empty
  • members, keys
  • include
  • lengthOf

Flags

  • not 
  • deep
  • nested
  • ordered
expect(result).to.have.nested.property("key.nestedKey", "value")
expect(result).to.include("some sub string")
expect(result).to.have.keys(["key1", "key2"])
expect(result).to.have.all.members(["item 1", "item 2"])
expect(result).to.match(/[a-zA-Z]/)
expect(result).to.equal("some string")
expect(result).to.deep.equal({ message: "some string" })
expect(result).to.not.equal("some string")
expect(result).to.have.lengthOf(3)

Equality

Matching

Examples

Kyle Coberly

kylecoberly.com

Intro to BDD Syntax

By Kyle Coberly

Intro to BDD Syntax

Lightning talk for DenverScript 9/24/19

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