Simplify integration with test frameworks

prebuild/prebuild.ts

@@ -1,5 +1,6 @@
 import { writeFileSync } from 'fs';
 import { generateProperty, generatePropertySpec } from './property';
+import { generateTest } from './test';
 import { generateTuple, generateTupleSpec } from './tuple';
 
 const NUM_PARAMETERS = 22;
@@ -10,5 +11,7 @@ writeFileSync('./test/unit/check/property/Property.generated.spec.ts', generateP
 writeFileSync('./src/check/property/AsyncProperty.generated.ts', generateProperty(NUM_PARAMETERS, true));
 writeFileSync('./test/unit/check/property/AsyncProperty.generated.spec.ts', generatePropertySpec(NUM_PARAMETERS, true));
 
+writeFileSync('./src/check/integration/Test.generated.ts', generateTest(NUM_PARAMETERS));
+
 writeFileSync('./src/check/arbitrary/TupleArbitrary.generated.ts', generateTuple(NUM_PARAMETERS));
 writeFileSync('./test/unit/check/arbitrary/TupleArbitrary.generated.spec.ts', generateTupleSpec(NUM_PARAMETERS));

prebuild/property.ts

@@ -1,6 +1,6 @@
 import { arbCommas, commas, iota, joiner, txCommas } from './helpers';
 
-const predicateFor = (num: number, isAsync: boolean): string =>
+export const predicateFor = (num: number, isAsync: boolean): string =>
   isAsync
     ? `(${commas(num, v => `t${v}:T${v}`)}) => Promise<boolean|void>`
     : `(${commas(num, v => `t${v}:T${v}`)}) => (boolean|void)`;

prebuild/test.ts

@@ -0,0 +1,71 @@
+import { commas, iota, joiner, txCommas } from './helpers';
+import { predicateFor } from './property';
+
+const testPredicateFor = (num: number) => `(${predicateFor(num, true)}) | (${predicateFor(num, false)})`;
+
+const signatureFor = (num: number): string => {
+  return `
+        /**
+         * Instanciate a new
+         * @param definition Test definition function of the test framework - eg.: it in Mocha
+         * @param label Label of the property
+         * ${joiner(num, v => `@param arb${v} Generate the parameter at position #${v + 1} of predicate`, '\n* ')}
+         * ${joiner(num, v => `@param predicate.t${v} Value generated by arb${v}`, '\n* ')}
+         * @param predicate Assess the success of the property. Would be considered falsy if its throws or if its output evaluates to false
+         */
+        function test<TestDefinitionOutput,${txCommas(num)}>(
+            definition: TestDefinition<TestDefinitionOutput>,
+            label: string,
+            ${commas(num, v => `arb${v}:Arbitrary<T${v}>`)},
+            predicate: ${testPredicateFor(num)}
+        ): void;`;
+};
+const finalSignatureFor = (num: number): string => {
+  return `
+        function test<TestDefinitionOutput,${txCommas(num)}>(
+            definition: TestDefinition<TestDefinitionOutput>,
+            label: string,
+            ${commas(num, v => `arb${v}?: Arbitrary<T${v}> | (${testPredicateFor(v)})`)},
+            arb${num}?: ${testPredicateFor(num)}
+        ) {`;
+};
+const ifFor = (num: number): string => {
+  return `
+        if (arb${num}) {
+            const seed = Date.now();
+            const p = arb${num} as ${testPredicateFor(num)};
+            const pp = async (${commas(num, v => `v${v}:T${v}`)}) => await p(${commas(num, v => `v${v}`)});
+            definition(label + " (seed: " + seed + ")", async () => {
+                await assert(
+                    asyncProperty(${commas(num, v => `arb${v} as Arbitrary<T${v}>`)}, pp),
+                    {seed: seed});
+            });
+            return;
+        }`;
+};
+
+const generateTest = (num: number): string => {
+  const blocks = [
+    // imports
+    `import Arbitrary from '../arbitrary/definition/Arbitrary';`,
+    `import { asyncProperty } from '../property/AsyncProperty';`,
+    `import { assert } from '../runner/Runner';`,
+    `import { TestDefinition } from './TestDefinition';`,
+    // declare all signatures
+    ...iota(num).map(id => signatureFor(id + 1)),
+    // start declare function
+    finalSignatureFor(num + 1),
+    // cascade ifs
+    ...iota(num)
+      .reverse()
+      .map(id => ifFor(id + 1)),
+    // end declare function
+    `}`,
+    // export
+    `export { test };`
+  ];
+
+  return blocks.join('\n');
+};
+
+export { generateTest };

src/check/integration/TestDefinition.ts

@@ -0,0 +1 @@
+export type TestDefinition<TestOutput> = (expectation: string, callback: () => PromiseLike<any>) => TestOutput;

src/fast-check-default.ts

@@ -1,5 +1,6 @@
 import 'core-js';
 
+import { test } from './check/integration/Test.generated';
 import { asyncProperty } from './check/property/AsyncProperty';
 import { property } from './check/property/Property';
 import { Parameters } from './check/runner/configuration/Parameters';
@@ -61,6 +62,7 @@ export {
   // check the property
   check,
   assert,
+  test,
   // property definition
   property,
   asyncProperty,