✅ Add tests for typings based on tsd (#464)

.travis.yml

@@ -39,12 +39,12 @@ jobs:
         - yarn format:check
         - yarn lint:check
     - stage: test
-      env: STEP=EXAMPLES_ROLLUP_LEGACY
+      env: STEP=EXAMPLES_ROLLUP_LEGACY_TYPES
       script:
         - yarn prebuild
+        - yarn build:publish-types
         - yarn build:publish-cjs
         - yarn build:publish-esm
-        - yarn build:publish-types
         - yarn webbuild
         - yarn link
         - cd example ;
@@ -54,6 +54,7 @@ jobs:
           cd ..
         - yarn test:rollup-esm
         - yarn test:rollup-iife
+        - yarn test:type
         - nvm install 0.12 ;
           node test/legacy/main.js
     - stage: test

package.json

@@ -30,6 +30,7 @@
     "e2e:watch": "jest --config jest.e2e.config.js --watch",
     "test:rollup-esm": "rollup --config test/rollup/esm/rollup.config.js && node test/rollup/esm/dist/main.js",
     "test:rollup-iife": "rollup --config test/rollup/iife/rollup.config.js && node test/rollup/iife/dist/main.js",
+    "test:type": "tsd",
     "coverage": "cat ./coverage/lcov.info | coveralls",
     "docs": "mkdir -p docs/2-API && docsify-init --editDir documentation && cp -R documentation/* docs/ && api-extractor run --local && generate-ts-docs markdown -i docs/2-API -o docs/2-API && cat README.md | sed 's/https:\\/\\/github.com\\/dubzzz\\/fast-check\\/blob\\/master\\/documentation//g' > docs/README.md && markdownbars -i docs/_sidebar.md -o docs/_sidebar.md",
     "format": "prettier --write \"**/*.{js,ts}\"",
@@ -75,6 +76,7 @@
     "source-map-support": "^0.5.13",
     "ts-jest": "^24.1.0",
     "ts-node": "^8.4.1",
+    "tsd": "^0.10.0",
     "tslint-config-prettier": "^1.18.0",
     "typescript": "^3.6.4",
     "uglifyjs": "^2.4.11"
@@ -87,5 +89,8 @@
     "quickcheck",
     "jscheck",
     "jsverify"
-  ]
+  ],
+  "tsd": {
+    "directory": "test/type"
+  }
 }

test/type/main.ts

@@ -0,0 +1,90 @@
+import { expectType, expectError } from 'tsd';
+import * as fc from '../../src/fast-check';
+
+// assert
+expectType<void>(fc.assert(fc.property(fc.nat(), () => {})));
+expectType<Promise<void>>(fc.assert(fc.asyncProperty(fc.nat(), async () => {})));
+
+// property
+expectType(fc.property(fc.nat(), a => {}) as fc.IProperty<[number]>);
+expectType(fc.property(fc.nat(), fc.string(), (a, b) => {}) as fc.IProperty<[number, string]>);
+expectError(fc.property(fc.nat(), fc.string(), (a: number, b: number) => {}));
+
+// asyncProperty
+expectType(fc.asyncProperty(fc.nat(), async a => {}) as fc.IAsyncProperty<[number]>);
+expectType(fc.asyncProperty(fc.nat(), fc.string(), async (a, b) => {}) as fc.IAsyncProperty<[number, string]>);
+expectError(fc.asyncProperty(fc.nat(), fc.string(), async (a: number, b: number) => {}));
+
+// record arbitrary
+expectType<fc.Arbitrary<{ a: number; b: string }>>(fc.record({ a: fc.nat(), b: fc.string() }));
+expectType<fc.Arbitrary<{ a?: number; b?: string }>>(
+  fc.record({ a: fc.nat(), b: fc.string() }, { withDeletedKeys: true })
+);
+expectError(fc.record({ a: 1 }));
+
+// dictionary arbitrary
+expectType<fc.Arbitrary<Record<string, number>>>(fc.dictionary(fc.string(), fc.nat()));
+expectError(fc.dictionary(fc.nat(), fc.nat()));
+
+// tuple arbitrary
+expectType<fc.Arbitrary<[number]>>(fc.tuple(fc.nat()));
+expectType<fc.Arbitrary<[number, string]>>(fc.tuple(fc.nat(), fc.string()));
+expectError(fc.tuple(fc.nat(), ''));
+
+// oneof arbitrary
+expectType<fc.Arbitrary<string>>(fc.oneof(fc.string(), fc.fullUnicodeString()));
+expectType<fc.Arbitrary<number | string>>(fc.oneof(fc.string() as fc.Arbitrary<number | string>, fc.nat()));
+expectError(fc.oneof(fc.string(), fc.nat())); // TODO Typings should be improved
+expectError(fc.oneof(fc.string(), '1'));
+
+// frequency arbitrary
+expectType<fc.Arbitrary<string>>(
+  fc.frequency({ arbitrary: fc.string(), weight: 1 }, { arbitrary: fc.fullUnicodeString(), weight: 1 })
+);
+expectType<fc.Arbitrary<number | string>>(
+  fc.frequency(
+    { arbitrary: fc.string() as fc.Arbitrary<number | string>, weight: 1 },
+    { arbitrary: fc.nat(), weight: 1 }
+  )
+);
+expectError(fc.frequency({ arbitrary: fc.string(), weight: 1 }, { arbitrary: fc.nat(), weight: 1 })); // TODO Typings should be improved
+expectError(fc.frequency({ arbitrary: fc.string(), weight: 1 }, { arbitrary: '1', weight: 1 }));
+
+// option arbitrary
+expectType<fc.Arbitrary<number | null>>(fc.option(fc.nat()));
+expectType<fc.Arbitrary<number | null>>(fc.option(fc.nat(), { nil: null }));
+expectType<fc.Arbitrary<number | 'custom_default'>>(fc.option(fc.nat(), { nil: 'custom_default' as const }));
+expectError(fc.option(1));
+
+// tie arbitrary
+expectType<{}>(fc.letrec(tie => ({})));
+expectType<{ a: fc.Arbitrary<number>; b: fc.Arbitrary<string> }>(
+  fc.letrec(tie => ({
+    a: fc.nat(),
+    b: fc.string()
+  }))
+);
+expectType<{ a: fc.Arbitrary<number>; b: fc.Arbitrary<unknown> }>(
+  fc.letrec(tie => ({
+    a: fc.nat(),
+    b: tie('a')
+  }))
+); // TODO Typings should be improved: b type might be infered from a
+expectType<{ a: fc.Arbitrary<number>; b: fc.Arbitrary<unknown> }>(
+  fc.letrec(tie => ({
+    a: fc.nat(),
+    b: tie('c')
+  }))
+); // TODO Typings should be improved: referencing an undefined key should failed
+
+// dedup arbitrary
+expectType<fc.Arbitrary<[]>>(fc.dedup(fc.nat(), 0));
+expectType<fc.Arbitrary<[number]>>(fc.dedup(fc.nat(), 1));
+expectType<fc.Arbitrary<[number, number]>>(fc.dedup(fc.nat(), 2));
+expectType<fc.Arbitrary<[number, number, number]>>(fc.dedup(fc.nat(), 3));
+expectType<fc.Arbitrary<[number, number, number, number]>>(fc.dedup(fc.nat(), 4));
+expectType<fc.Arbitrary<number[]>>(fc.dedup(fc.nat(), 5)); // TODO Typings should be improved: handle any number of values
+
+// func arbitrary
+expectType<fc.Arbitrary<() => number>>(fc.func(fc.nat()));
+expectError(fc.func(1));