Static Swift Code AnalysisThe Background Story

HelsinkiOS March 2017Jouni Miettunen @jomtwiZalando Helsinki

Jouni Miettunen at HelsinkiOS March, 2017 1

What

• Oriented graph of dependencies between classes

• Objective-C has objc_dep

"Class A depends on B if class A imports class B header"

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Why

Discover real (sub) architecture

• New features with existing APIs

• Maintenance & bug fixes

• Refactor technical dept

• Curious or new people

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What about swift?

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Compiled object files

• App / framework sources

• Fix project settings

• Update to latest swift

• Build project

• Parse compiled object files

• Open the graph

• Profit !!!

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Want

• Fast

• Easy

• Configure

• Parse whatever

• Profit !!!

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Work in progress...

Hackweek #5Zalando Open SourceHow to Open Source at Zalando

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Phase 0: basics

• python

• One file or folder tree

• One line, regex

• Ignore

• swift keywords

• swift vs. Objective-C frameworks (71)

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Phase 1: import framework

import-kind → typealias struct class enum protocol var func

The Swift Programming Language (Swift 3.0.1)

// Easy

import Foundation

@testable import MyFramework

// What to do

import func MyFramework.debugLog

import class MyFramework.DebugLogger

import enum MyFramework.DebugLevel

import class MyFramework.UIButton

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Phase 2: class inheritance

• class, protocol, struct, enum

• generics, extensions, typealias

internal final class MyClass {}class SomeClass: Superclass, FirstProtocol {}open class Event <ElementA, ElementB>: EventType {}@objc protocol MyDelegate: OtherDelegate {}public protocol OwnProtocol: class {}

"Extensions can add new nested types to existing classes, structures, and enumerations"Jouni Miettunen at HelsinkiOS March, 2017 10

Phase 3: class usage

1.Definitions

2.Namespace {} and strings

3.Ignore and match

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Phase 4: decoration

• UI via Graphviz

• Type shapes and colors

• Point of view

• Lonely

• Circular dependencies

• Risk(ish) analysis

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Phase 5: future

• Continuous integration

• More circular dependencies

• Unused code

• Internal modules

• Any language

• Profit !!!

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Thank You!! We're hiring, too

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Profit !!!

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The Others

• objc_dep

• Refactorator II, The App

• Objective-C Class Dependencies Visualizer

• Swift relationship graph

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