The Scandalous Story of the Dreadful Code Written by the Best of Us

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The Scandalous Story of the Dreadful Code Written by the Best of Us Katrina Owen ! GitHub

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I never get the notifications when we run out of stuff.

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resource depleted

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Alice reports that we are out of ammo. TEXT

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Alice says we're running low on ammo. HTML

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copy | paste

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package notify

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it's totally fine

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// TODO: add tests

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package comms func Broadcast(s string, f game.Freq, c Crypto) { // ... a mountain of complexity... } func Dispatch(s string, p *game.Person) { // ... horrible things... } func Register(e game.Event, p *game.Person) { // ... kind of confusing stuff... }

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Did the message say the right thing?

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Did the right people get the message?

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\o/

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The No-op No-op No-op Interface Maneuver

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one undo

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no-op #1

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package comms type Signal struct{} no-op #1

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package comms type Signal struct{} func (*Signal) Broadcast(s string, f game.Freq, c Crypto) { } func (*Signal) Dispatch(s string, p *game.Person) { } func (*Signal) Register(e game.Event, p *game.Person) { } no-op #1

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package comms func Broadcast(s string, f game.Freq, c Crypto) { // ... a mountain of complexity... Sig.Broadcast(s, f, c) } func Dispatch(s string, p *game.Person) { // ... horrible things... Sig.Dispatch(s, p) } func Register(e game.Event, p *game.Person) { // ... kind of confusing stuff... Sig.Register(e, p) } no-op #1

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package comms var Sig *Signal func (*Signal) Broadcast(s string, f game.Freq, c Crypto) { } func (*Signal) Dispatch(s string, p *game.Person) { } func (*Signal) Register(e game.Event, p *game.Person) { } no-op #1

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no-op #1

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no-op #2

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no-op #2 package comms func Broadcast(s string, f game.Freq, c Crypto) { // ... a mountain of complexity... Sig.Broadcast(s, f, c) }

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no-op #2 package comms func Broadcast(s string, f game.Freq, c Crypto) { // ... a mountain of complexity... Sig.Broadcast(s, f, c) }

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no-op #2 package comms func Broadcast(s string, f game.Freq, c Crypto) { // ... a mountain of complexity... Sig.Broadcast(s, f, c) }

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no-op #2 package comms func Broadcast(s string, f game.Freq, c Crypto) { // ... a mountain of complexity... Sig.Broadcast(s, f, c) } func (*Signal) Broadcast(s string, f game.Freq, c Crypto) { }

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no-op #2 package comms func Broadcast(s string, f game.Freq, c Crypto) { // ... a mountain of complexity... Sig.Broadcast(s, f, c) } func (*Signal) Broadcast(s string, f game.Freq, c Crypto) { }

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no-op #2 package comms func Broadcast(s string, f game.Freq, c Crypto) { Sig.Broadcast(s, f, c) } func (*Signal) Broadcast(s string, f game.Freq, c Crypto) { // ... a mountain of complexity... }

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no-op #2

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no-op #3

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no-op #3 package notify func ResourceDepleted(r game.Resource, p *game.Person) { // ... comms.Broadcast(...) // ... }

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no-op #3 package notify func ResourceDepleted(com *comms.Signal, r game.Resource, p *game.Person ) { // ... comms.Broadcast(...) // ... }

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package api notify.ResourceDepleted(comms.Sig, resource, person) no-op #3

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no-op #3 package notify func ResourceDepleted(com *comms.Signal, r game.Resource, p *game.Person ) { // ... comms.Broadcast(...) // ... }

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package notify func ResourceDepleted(com *comms.Signal, r game.Resource, p *game.Person ) { // ... com.Broadcast(...) // ... } no-op #3

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package comms func Broadcast(s string, f game.Freq, c Crypto) { Sig.Broadcast(s, f, c) } func Dispatch(s string, p *game.Person) { Sig.Dispatch(s, p) } func Register(e game.Event, p *game.Person) { Sig.Register(e, p) } no-op #3

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no-op #3 package comms

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no-op #3

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interface

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package comms type Transmitter interface { Broadcast(string, game.Freq, Crypto) Dispatch(string, *game.Person) Register(game.Event, *game.Person) } interface

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interface package notify func ResourceDepleted(com *comms.Signal, r game.Resource, p *game.Person ) { // ... com.Broadcast(...) // ... }

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interface package notify func ResourceDepleted(com *comms.Signal, r game.Resource, p *game.Person ) { // ... com.Broadcast(...) // ... }

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interface package notify func ResourceDepleted(com comms.Transmitter, r game.Resource, p *game.Person ) { // ... com.Broadcast(...) // ... }

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interface package notify type fakeTransmitter struct { broadcasts []fakeBroadcast dispatches []fakeDispatch events []fakeEvent }

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package notify type fakeTransmitter struct { broadcasts []fakeBroadcast dispatches []fakeDispatch events []fakeEvent } func (*fakeTransmitter) Broadcast(...) { } func (*fakeTransmitter) Dispatch(...) { } func (*fakeTransmitter) Register(...) { } interface

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no-op no-op no-op interface maneuver

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clean code

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The Flocking Rules

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find the things that are most alike rule #1

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select the smallest difference between them rule #2

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make the smallest change that will remove that difference rule #3

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the flocking rules

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resource found

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text vs html

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text := fmt.Sprintf( "%s discovered %s at %s.", p.Name, r.Name, loc, )

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text := fmt.Sprintf( "%s discovered %s at %s.", p.Name, r.Name, loc, )

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text := fmt.Sprintf( "%s discovered %s at %s.", p.Name, r.Name, loc, )

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html := fmt.Sprintf( "%s discovered "+ "%s"+ " at %s.", p.Handle, template.HTMLEscapeString(p.Name), r.TribeUUID(), r.UUID, template.HTMLEscapeString(r.Name), loc.Latitude, loc.Longitude, template.HTMLEscapeString(loc.String()), )

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find the things that are most alike rule #1

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text := fmt.Sprintf( "%s discovered %s at %s.", p.Name, r.Name, loc, ) html := fmt.Sprintf( "%s discovered "+ "%s "+ "at %s.", p.Handle, template.HTMLEscapeString(p.Name), r.TribeUUID(), r.UUID, template.HTMLEscapeString(r.Name), loc.Latitude, loc.Longitude, template.HTMLEscapeString(loc.String()), )

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text := fmt.Sprintf( "%s discovered %s at %s.", v1, v2, v3, ) html := fmt.Sprintf( "%s discovered "+ "%s "+ "at %s.", v4, v5, v6, v7, v8, v9, v10, v11, )

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text := fmt.Sprintf( "%s discovered %s at %s.", v1, v2, v3, ) html := fmt.Sprintf( "%s discovered "+ "%s "+ "at %s.", v4, v5, v6, v7, v8, v9, v10, v11, )

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select the smallest difference between them rule #2

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text := fmt.Sprintf( "%s discovered %s at %s.", v1, v2, v3, ) html := fmt.Sprintf( "%s discovered "+ "%s "+ "at %s.", v4, v5, v6, v7, v8, v9, v10, v11, )

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text := fmt.Sprintf( "%s discovered %s at %s.", v1, v2, v3, ) html := fmt.Sprintf( "%s discovered "+ "%s "+ "at %s.", v4, v5, v6, v7, v8, v9, v10, v11, )

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text := fmt.Sprintf( "%s discovered %s at %s.", v1, v2, v3, ) html := fmt.Sprintf( "%s discovered "+ "%s "+ "at %s.", v4, v5, v6, v7, v8, v9, v10, v11, )

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text := fmt.Sprintf( "%s discovered %s at %s.", v1, v2, v3, ) html := fmt.Sprintf( "%s discovered "+ "%s "+ "at %s.", v4, v5, v6, v7, v8, v9, v10, v11, )

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make the smallest change that will remove that difference rule #3

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text := fmt.Sprintf( "%s discovered %s at %s.", v1, v2, v3, ) html := fmt.Sprintf( "%s discovered "+ "%s "+ "at %s.", v4, v5, v6, v7, v8, v9, v10, v11, )

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text := fmt.Sprintf( "%s discovered %s at %s.", v1, v2, v3, ) html := fmt.Sprintf( "%s discovered %s at %s.", anchor1, anchor2, anchor3, )

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text := fmt.Sprintf( "%s discovered %s at %s.", v1, v2, v3, ) html := fmt.Sprintf( "%s discovered %s at %s.", anchor1, anchor2, anchor3, )

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anchor1 := fmt.Sprintf( "%s", p.Handle, template.HTMLEscapeString(p.Name), ) anchor2 := fmt.Sprintf( "%s", r.TribeUUID(), r.UUID, template.HTMLEscapeString(r.Name), ) anchor3 := fmt.Sprintf( "%s", loc.Latitude, loc.Longitude, template.HTMLEscapeString(loc.String()), )

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text := fmt.Sprintf( "%s discovered %s at %s.", v1, v2, v3, ) html := fmt.Sprintf( "%s discovered %s at %s.", anchor1, anchor2, anchor3, )

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msg := "%s discovered %s at %s." text := fmt.Sprintf( msg, v1, v2, v3, ) html := fmt.Sprintf( msg, anchor1, anchor2, anchor3, )

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find the things that are most alike rule #1

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select the smallest difference between them rule #2

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make the smallest change that will remove that difference rule #3

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anchor1 := fmt.Sprintf( "%s", p.URL(), template.HTMLEscapeString(p.Name), ) anchor2 := fmt.Sprintf( "%s", r.URL(), template.HTMLEscapeString(r.Name), ) anchor3 := fmt.Sprintf( "%s", loc.URL(), template.HTMLEscapeString(loc.String()), )

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find the things that are most alike rule #1

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select the smallest difference between them rule #2

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make the smallest change that will remove that difference rule #3

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anchor1 := fmt.Sprintf( "%s", p.URL(), template.HTMLEscapeString(p.String()), ) anchor2 := fmt.Sprintf( "%s", r.URL(), template.HTMLEscapeString(r.String()), ) anchor3 := fmt.Sprintf( "%s", loc.URL(), template.HTMLEscapeString(loc.String()), )

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find the things that are most alike rule #1

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select the smallest difference between them rule #2

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make the smallest change that will remove that difference rule #3

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type linker interface { String() string URL() string }

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type linker interface { String() string URL() string }

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func link(l linker) string { fmt.Sprintf( "%s", p.URL(), template.HTMLEscapeString(p.String()), ) }

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func link(l linker) string { return fmt.Sprintf( "%s", l.URL(), template.HTMLEscapeString(l.String()), ) }

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func link(l linker) string { return fmt.Sprintf( "%s", l.URL(), template.HTMLEscapeString(l.String()), ) }

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find the things that are most alike rule #1

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msg := "%s discovered %s at %s." text := fmt.Sprintf( msg, p.Name, r.Name, loc, ) html := fmt.Sprintf( msg, link(p), link(r), link(loc), )

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msg := "%s discovered %s at %s." text := fmt.Sprintf( msg, p.Name, r.Name, loc, ) html := fmt.Sprintf( msg, link(p), link(r), link(loc), )

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select the smallest difference between them rule #2

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msg := "%s discovered %s at %s." text := fmt.Sprintf( msg, p.Name, r.Name, loc, ) html := fmt.Sprintf( msg, link(p), link(r), link(loc), )

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msg := "%s discovered %s at %s." text := fmt.Sprintf( msg, p.Name, r.Name, loc, ) html := fmt.Sprintf( msg, link(p), link(r), link(loc), )

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msg := "%s discovered %s at %s." text := fmt.Sprintf( msg, p.Name, r.Name, loc, ) html := fmt.Sprintf( msg, link(p), link(r), link(loc), )

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make the smallest change that will remove that difference rule #3

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msg := "%s discovered %s at %s." text := fmt.Sprintf( msg, p, r, loc, ) html := fmt.Sprintf( msg, link(p), link(r), link(loc), )

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find the things that are most alike rule #1

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msg := "%s discovered %s at %s." text := fmt.Sprintf( msg, p, r, loc, ) html := fmt.Sprintf( msg, link(p), link(r), link(loc), )

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select the smallest difference between them rule #2

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msg := "%s discovered %s at %s." text := fmt.Sprintf( msg, p, r, loc, ) html := fmt.Sprintf( msg, link(p), link(r), link(loc), )

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make the smallest change that will remove that difference rule #3

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func text(l linker) string { return l.String() }

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msg := "%s discovered %s at %s." text := fmt.Sprintf( msg, text(p), text(r), text(loc), ) html := fmt.Sprintf( msg, link(p), link(r), link(loc), )

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find the things that are most alike rule #1

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msg := "%s discovered %s at %s." text := fmt.Sprintf( msg, text(p), text(r), text(loc), ) html := fmt.Sprintf( msg, link(p), link(r), link(loc), )

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select the smallest difference between them rule #2

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msg := "%s discovered %s at %s." text := fmt.Sprintf( msg, text(p), text(r), text(loc), ) html := fmt.Sprintf( msg, link(p), link(r), link(loc), )

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make the smallest change that will remove that difference rule #3

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func text(l linker) string { return l.String() } func link(l linker) string { return fmt.Sprintf( "%s", l.URL(), template.HTMLEscapeString(l.String()), ) }

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func format(fn func(linker) string) string { // ... }

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func format(..., fn func(linker) string, ...) string { // ... }

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func format(msg string, fn func(linker) str... args := make([]interface{}, len(values)) for i, v := range values { args[i] = fn(v) } return fmt.Sprintf(msg, args...) }

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func format(msg string, fn func(linker) str... args := make([]interface{}, len(values)) for i, v := range values { args[i] = fn(v) } return fmt.Sprintf(msg, args...) }

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msg := "%s discovered %s at %s." text := fmt(msg, text, p, r, loc) html := fmt(msg, link, p, r, loc)

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type message struct { template string vars []linker } func newMessage(template string, vars ...linker) message { return message{ template: template, vars: vars, } }

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func (msg message) fmt(fn func(linker) string) string { args := make([]interface{}, len(msg.vars)) for i, v := range msg.vars { args[i] = fn(v) } return fmt.Sprintf(msg.template, args...) }

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func (msg message) text() string { return msg.fmt(text) } func (msg message) html() string { return msg.fmt(link) }

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s := "%s discovered %s at %s." msg := newMessage(s, p, r, loc) // ... msg.text() // ... msg.html()

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type message struct { template string vars []linker } func newMessage(template string, vars ...linker) message { return message{ template: template, vars: vars, } }

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type message struct { template string vars []linker } func (msg message) text() string { return msg.fmt(text) } func (msg message) html() string { return msg.fmt(link) } func (msg message) fmt(fn func(linker) string) string { args := make([]interface{}, len(msg.vars)) for i, v := range msg.vars { args[i] = fn(v) } return fmt.Sprintf(msg.template, args...) }

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type linker interface { String() string URL() string } func link(l linker) string { return fmt.Sprintf( "%s", l.URL(), template.HTMLEscapeString(l.String()), ) } func text(l linker) string { return l.String() }