Bugs - What are they good for

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1 Bugs What are they good for?

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What is a bug?

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“First actual case of bug being found” Grace Hopper - 1947

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“I did find a bug in my apparatus” Thomas Edison - 1878

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The Crash <> Request Scale Crash Change Request ⚠

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Let’s ship some products

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Numbers only?

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Nope

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“You didn’t say you wanted to ship stuff to the Queen”

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“Well you should know how addresses work”

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The Crash <> Request Scale Crash Change Request ⚠

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Record Investigate Fix

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Reproduce It Fix It Ship It

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Find a reproducible scenario

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Speeds up ﬁxing process

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accepted Closed Won

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paid Closed Lost

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context 'accepted order' do let(:order) { build(:order, status: 'accepted') } it 'returns "closed won"' do expect(deal_stage(order)).to eq('closed won') end end context 'paid order' do let(:order) { build(:order, status: 'paid') } it 'returns "closed won"' do expect(deal_stage(order)).to eq('closed won') end end

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def deal_stage(order) return 'enquired' if order.nil? return 'quoted' if order.open? return 'closed won' if order.accepted? 'closed lost' end

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Lets you try out different solutions

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Makes it clear what to ﬁx

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NoMethodError: undefined method `date’ for nil:NilClass

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def render(order) { id: order.id, delivery_date: order.delivery.date } end

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def render(order) { id: order.id, delivery_date: order.delivery&.date } end

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GET /api/v1/orders?status=delivered • Order 01 • Order 02 • Order 03

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Conﬁdence that bug has been ﬁxed

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Continuous Integration Heroku Review Apps Create App Precompile Assets Create/Migrate Database Launch App Code

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But what about actually ﬁxing the bugs?

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def deal_stage(order) puts "What's happening?: #{order.inspect}" return 'enquired' if order.nil? puts "What's happening?: #{order.inspect}" return 'quoted' if order.open? puts "What's happening?: #{order.inspect}" return 'closed won' if order.accepted? puts "What's happening?: #{order.inspect}" 'closed lost' end Puts Debugging

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github.com/pry/pry def deal_stage(order) binding.pry return 'enquired' if order.nil? return 'quoted' if order.open? return 'closed won' if order.accepted? 'closed lost' end