fast-check

https://gyazo.com/0f88c371e2bf6e22f360b30ffc3e8c81

fast-checkによってOSSのバグが見つかった実例

特別な設定は不要そう

global settings

生成するケース数とか

code:ts

fc.property(...arbitraries, (...args) => {});

例

code:ts

fc.assert(

fc.property(fc.string(), fc.string(), fc.string(), (a, b, c) => {

return contains(a + b + c, b);

}),

);

3つのstring値を生成してる

テスト用にもCommandとその事前条件を定義しておき、事前条件を満たすものだけを、ランダムに投げていくテスト

code:ts

class AddBookNewCommand implements fc.Command<Model, BookRepository> {

constructor(readonly value: Book) {}

check = (m: Readonly<Model>) => {

return !hasIsbn(m, this.value.isbn);

};

async run(m: Model, r: BookRepository): Promise<void> {

await r.addBook(

this.value.isbn,

this.value.title,

this.value.author,

this.value.owned,

this.value.available

);

m.set(this.value.isbn, this.value);

}

}

classで作るんだ

introduction

core-blocks

properties.md

advanced

fake-data.md

fuzzing.md

model-based-testing.md

race-conditions.md

configuration

custom-reports.md

global-settings.md

index.md

larger-entries-by-default.md

timeouts.md

user-definable-values.md

ecosystem.md

tutorials

quick-start

detect-race-conditions

index.md

multiple-batches-of-calls.mdx

one-step-closer-to-real-usages.mdx

snippets.mjs

snippets.spec.mjs

the-missing-part.mdx

wrapping-up.mdx

your-first-race-condition-test.mdx

index.md