✨ Generate dangerous strings by default

.yarn/versions/82fcb103.yml

@@ -0,0 +1,25 @@
+releases:
+  fast-check: minor
+
+declined:
+  - "@fast-check/monorepo"
+  - "@fast-check/examples"
+  - "@fast-check/ava"
+  - "@fast-check/jest"
+  - "@fast-check/packaged"
+  - "@fast-check/test-ava-bundle-cjs"
+  - "@fast-check/test-ava-bundle-esm"
+  - "@fast-check/test-bundle-esbuild-with-import"
+  - "@fast-check/test-bundle-esbuild-with-require"
+  - "@fast-check/test-bundle-node-extension-cjs"
+  - "@fast-check/test-bundle-node-extension-mjs"
+  - "@fast-check/test-bundle-node-with-import"
+  - "@fast-check/test-bundle-node-with-require"
+  - "@fast-check/test-bundle-rollup-with-import"
+  - "@fast-check/test-bundle-rollup-with-require"
+  - "@fast-check/test-bundle-webpack-with-import"
+  - "@fast-check/test-bundle-webpack-with-require"
+  - "@fast-check/test-jest-bundle-cjs"
+  - "@fast-check/test-jest-bundle-esm"
+  - "@fast-check/test-minimal-support"
+  - "@fast-check/test-types"

packages/fast-check/src/arbitrary/_internals/helpers/SlicesForStringBuilder.ts

@@ -0,0 +1,67 @@
+import { Arbitrary } from '../../../check/arbitrary/definition/Arbitrary';
+
+const dangerousStrings = [
+  // Default attributes on raw Object (from ({}).*)
+  '__defineGetter__',
+  '__defineSetter__',
+  '__lookupGetter__',
+  '__lookupSetter__',
+  '__proto__',
+  'constructor',
+  'hasOwnProperty',
+  'isPrototypeOf',
+  'propertyIsEnumerable',
+  'toLocaleString',
+  'toString',
+  'valueOf',
+  // Other classical defaults (from MyClassName.*)
+  'apply',
+  'arguments',
+  'bind',
+  'call',
+  'caller',
+  'length',
+  'name',
+  'prototype',
+  // React
+  'key',
+  'ref',
+];
+
+/** @internal */
+function computeCandidateString(
+  dangerous: string,
+  charArbitrary: Arbitrary<string>,
+  stringSplitter: (value: string) => string[]
+): string[] | undefined {
+  let candidate: string[];
+  try {
+    candidate = stringSplitter(dangerous);
+  } catch (err) {
+    // No split found for `dangerous`, `dangerous` cannot be shrunk by arrays made of `charArbitrary`
+    return undefined;
+  }
+  for (const entry of candidate) {
+    if (!charArbitrary.canShrinkWithoutContext(entry)) {
+      // Item `entry` cannot be shrunk by `charArbitrary` thus we cannot keep this candidate
+      // Remark: depending on the passed `stringSplitter` this check may already have been done
+      return undefined;
+    }
+  }
+  return candidate;
+}
+
+/** @internal */
+export function createSlicesForString(
+  charArbitrary: Arbitrary<string>,
+  stringSplitter: (value: string) => string[]
+): string[][] {
+  const slicesForString: string[][] = [];
+  for (const dangerous of dangerousStrings) {
+    const candidate = computeCandidateString(dangerous, charArbitrary, stringSplitter);
+    if (candidate) {
+      slicesForString.push(candidate);
+    }
+  }
+  return slicesForString;
+}

packages/fast-check/src/arbitrary/asciiString.ts

@@ -1,8 +1,9 @@
 import { Arbitrary } from '../check/arbitrary/definition/Arbitrary';
-import { array } from './array';
+import { array, ArrayConstraintsInternal } from './array';
 import { ascii } from './ascii';
 import { StringSharedConstraints } from './_shared/StringSharedConstraints';
 import { codePointsToStringMapper, codePointsToStringUnmapper } from './_internals/mappers/CodePointsToString';
+import { createSlicesForString } from './_internals/helpers/SlicesForStringBuilder';
 export { StringSharedConstraints } from './_shared/StringSharedConstraints';
 
 /**
@@ -14,5 +15,8 @@ export { StringSharedConstraints } from './_shared/StringSharedConstraints';
  * @public
  */
 export function asciiString(constraints: StringSharedConstraints = {}): Arbitrary<string> {
-  return array(ascii(), constraints).map(codePointsToStringMapper, codePointsToStringUnmapper);
+  const charArbitrary = ascii();
+  const experimentalCustomSlices = createSlicesForString(charArbitrary, codePointsToStringUnmapper);
+  const enrichedConstraints: ArrayConstraintsInternal<string> = { ...constraints, experimentalCustomSlices };
+  return array(charArbitrary, enrichedConstraints).map(codePointsToStringMapper, codePointsToStringUnmapper);
 }

packages/fast-check/src/arbitrary/base64String.ts

@@ -1,10 +1,11 @@
 import { Arbitrary } from '../check/arbitrary/definition/Arbitrary';
-import { array } from './array';
+import { array, ArrayConstraintsInternal } from './array';
 import { base64 } from './base64';
 import { MaxLengthUpperBound } from './_internals/helpers/MaxLengthFromMinLength';
 import { StringSharedConstraints } from './_shared/StringSharedConstraints';
 import { codePointsToStringMapper, codePointsToStringUnmapper } from './_internals/mappers/CodePointsToString';
 import { stringToBase64Mapper, stringToBase64Unmapper } from './_internals/mappers/StringToBase64';
+import { createSlicesForString } from './_internals/helpers/SlicesForStringBuilder';
 export { StringSharedConstraints } from './_shared/StringSharedConstraints';
 
 /**
@@ -28,7 +29,15 @@ function base64String(constraints: StringSharedConstraints = {}): Arbitrary<stri
   if (minLength % 4 !== 0) throw new Error('Minimal length of base64 strings must be a multiple of 4');
   if (maxLength % 4 !== 0) throw new Error('Maximal length of base64 strings must be a multiple of 4');
 
-  return array(base64(), { minLength, maxLength, size: requestedSize })
+  const charArbitrary = base64();
+  const experimentalCustomSlices = createSlicesForString(charArbitrary, codePointsToStringUnmapper);
+  const enrichedConstraints: ArrayConstraintsInternal<string> = {
+    minLength,
+    maxLength,
+    size: requestedSize,
+    experimentalCustomSlices,
+  };
+  return array(charArbitrary, enrichedConstraints)
     .map(codePointsToStringMapper, codePointsToStringUnmapper)
     .map(stringToBase64Mapper, stringToBase64Unmapper);
 }

packages/fast-check/src/arbitrary/fullUnicodeString.ts

@@ -1,8 +1,9 @@
 import { Arbitrary } from '../check/arbitrary/definition/Arbitrary';
-import { array } from './array';
+import { array, ArrayConstraintsInternal } from './array';
 import { fullUnicode } from './fullUnicode';
 import { StringSharedConstraints } from './_shared/StringSharedConstraints';
 import { codePointsToStringMapper, codePointsToStringUnmapper } from './_internals/mappers/CodePointsToString';
+import { createSlicesForString } from './_internals/helpers/SlicesForStringBuilder';
 export { StringSharedConstraints } from './_shared/StringSharedConstraints';
 
 /**
@@ -14,5 +15,8 @@ export { StringSharedConstraints } from './_shared/StringSharedConstraints';
  * @public
  */
 export function fullUnicodeString(constraints: StringSharedConstraints = {}): Arbitrary<string> {
-  return array(fullUnicode(), constraints).map(codePointsToStringMapper, codePointsToStringUnmapper);
+  const charArbitrary = fullUnicode();
+  const experimentalCustomSlices = createSlicesForString(charArbitrary, codePointsToStringUnmapper);
+  const enrichedConstraints: ArrayConstraintsInternal<string> = { ...constraints, experimentalCustomSlices };
+  return array(charArbitrary, enrichedConstraints).map(codePointsToStringMapper, codePointsToStringUnmapper);
 }

packages/fast-check/src/arbitrary/hexaString.ts

@@ -1,8 +1,9 @@
 import { Arbitrary } from '../check/arbitrary/definition/Arbitrary';
-import { array } from './array';
+import { array, ArrayConstraintsInternal } from './array';
 import { hexa } from './hexa';
 import { StringSharedConstraints } from './_shared/StringSharedConstraints';
 import { codePointsToStringMapper, codePointsToStringUnmapper } from './_internals/mappers/CodePointsToString';
+import { createSlicesForString } from './_internals/helpers/SlicesForStringBuilder';
 export { StringSharedConstraints } from './_shared/StringSharedConstraints';
 
 /**
@@ -14,6 +15,9 @@ export { StringSharedConstraints } from './_shared/StringSharedConstraints';
  * @public
  */
 function hexaString(constraints: StringSharedConstraints = {}): Arbitrary<string> {
-  return array(hexa(), constraints).map(codePointsToStringMapper, codePointsToStringUnmapper);
+  const charArbitrary = hexa();
+  const experimentalCustomSlices = createSlicesForString(charArbitrary, codePointsToStringUnmapper);
+  const enrichedConstraints: ArrayConstraintsInternal<string> = { ...constraints, experimentalCustomSlices };
+  return array(charArbitrary, enrichedConstraints).map(codePointsToStringMapper, codePointsToStringUnmapper);
 }
 export { hexaString };

packages/fast-check/src/arbitrary/string.ts

@@ -1,8 +1,9 @@
 import { Arbitrary } from '../check/arbitrary/definition/Arbitrary';
-import { array } from './array';
+import { array, ArrayConstraintsInternal } from './array';
 import { char } from './char';
 import { StringSharedConstraints } from './_shared/StringSharedConstraints';
 import { codePointsToStringMapper, codePointsToStringUnmapper } from './_internals/mappers/CodePointsToString';
+import { createSlicesForString } from './_internals/helpers/SlicesForStringBuilder';
 export { StringSharedConstraints } from './_shared/StringSharedConstraints';
 
 /**
@@ -14,5 +15,8 @@ export { StringSharedConstraints } from './_shared/StringSharedConstraints';
  * @public
  */
 export function string(constraints: StringSharedConstraints = {}): Arbitrary<string> {
-  return array(char(), constraints).map(codePointsToStringMapper, codePointsToStringUnmapper);
+  const charArbitrary = char();
+  const experimentalCustomSlices = createSlicesForString(charArbitrary, codePointsToStringUnmapper);
+  const enrichedConstraints: ArrayConstraintsInternal<string> = { ...constraints, experimentalCustomSlices };
+  return array(charArbitrary, enrichedConstraints).map(codePointsToStringMapper, codePointsToStringUnmapper);
 }

packages/fast-check/src/arbitrary/string16bits.ts

@@ -1,8 +1,9 @@
 import { Arbitrary } from '../check/arbitrary/definition/Arbitrary';
-import { array } from './array';
+import { array, ArrayConstraintsInternal } from './array';
 import { char16bits } from './char16bits';
 import { StringSharedConstraints } from './_shared/StringSharedConstraints';
 import { charsToStringMapper, charsToStringUnmapper } from './_internals/mappers/CharsToString';
+import { createSlicesForString } from './_internals/helpers/SlicesForStringBuilder';
 export { StringSharedConstraints } from './_shared/StringSharedConstraints';
 
 /**
@@ -14,5 +15,8 @@ export { StringSharedConstraints } from './_shared/StringSharedConstraints';
  * @public
  */
 export function string16bits(constraints: StringSharedConstraints = {}): Arbitrary<string> {
-  return array(char16bits(), constraints).map(charsToStringMapper, charsToStringUnmapper);
+  const charArbitrary = char16bits();
+  const experimentalCustomSlices = createSlicesForString(charArbitrary, charsToStringUnmapper);
+  const enrichedConstraints: ArrayConstraintsInternal<string> = { ...constraints, experimentalCustomSlices };
+  return array(charArbitrary, enrichedConstraints).map(charsToStringMapper, charsToStringUnmapper);
 }

packages/fast-check/src/arbitrary/stringOf.ts

@@ -1,7 +1,8 @@
 import { Arbitrary } from '../check/arbitrary/definition/Arbitrary';
-import { array } from './array';
+import { array, ArrayConstraintsInternal } from './array';
 import { StringSharedConstraints } from './_shared/StringSharedConstraints';
 import { patternsToStringMapper, patternsToStringUnmapperFor } from './_internals/mappers/PatternsToString';
+import { createSlicesForString } from './_internals/helpers/SlicesForStringBuilder';
 export { StringSharedConstraints } from './_shared/StringSharedConstraints';
 
 /**
@@ -14,5 +15,8 @@ export { StringSharedConstraints } from './_shared/StringSharedConstraints';
  * @public
  */
 export function stringOf(charArb: Arbitrary<string>, constraints: StringSharedConstraints = {}): Arbitrary<string> {
-  return array(charArb, constraints).map(patternsToStringMapper, patternsToStringUnmapperFor(charArb, constraints));
+  const unmapper = patternsToStringUnmapperFor(charArb, constraints);
+  const experimentalCustomSlices = createSlicesForString(charArb, unmapper);
+  const enrichedConstraints: ArrayConstraintsInternal<string> = { ...constraints, experimentalCustomSlices };
+  return array(charArb, enrichedConstraints).map(patternsToStringMapper, unmapper);
 }

packages/fast-check/src/arbitrary/unicodeString.ts

@@ -1,8 +1,9 @@
 import { Arbitrary } from '../check/arbitrary/definition/Arbitrary';
-import { array } from './array';
+import { array, ArrayConstraintsInternal } from './array';
 import { unicode } from './unicode';
 import { StringSharedConstraints } from './_shared/StringSharedConstraints';
 import { codePointsToStringMapper, codePointsToStringUnmapper } from './_internals/mappers/CodePointsToString';
+import { createSlicesForString } from './_internals/helpers/SlicesForStringBuilder';
 export { StringSharedConstraints } from './_shared/StringSharedConstraints';
 
 /**
@@ -14,5 +15,8 @@ export { StringSharedConstraints } from './_shared/StringSharedConstraints';
  * @public
  */
 export function unicodeString(constraints: StringSharedConstraints = {}): Arbitrary<string> {
-  return array(unicode(), constraints).map(codePointsToStringMapper, codePointsToStringUnmapper);
+  const charArbitrary = unicode();
+  const experimentalCustomSlices = createSlicesForString(charArbitrary, codePointsToStringUnmapper);
+  const enrichedConstraints: ArrayConstraintsInternal<string> = { ...constraints, experimentalCustomSlices };
+  return array(charArbitrary, enrichedConstraints).map(codePointsToStringMapper, codePointsToStringUnmapper);
 }