improve mechanics and test coverage for largeArraySize-option (#575)

Author: Uzlopak

index.js

@@ -107,10 +107,14 @@ function build (schema, options) {
   }
 
   if (options.largeArraySize) {
-    if (!Number.isNaN(Number.parseInt(options.largeArraySize, 10))) {
+    if (typeof options.largeArraySize === 'string' && Number.isFinite(Number.parseInt(options.largeArraySize, 10))) {
+      largeArraySize = Number.parseInt(options.largeArraySize, 10)
+    } else if (typeof options.largeArraySize === 'number' && Number.isInteger(options.largeArraySize)) {
       largeArraySize = options.largeArraySize
+    } else if (typeof options.largeArraySize === 'bigint') {
+      largeArraySize = Number(options.largeArraySize)
     } else {
-      throw new Error(`Unsupported large array size. Expected integer-like, got ${options.largeArraySize}`)
+      throw new Error(`Unsupported large array size. Expected integer-like, got ${typeof options.largeArraySize} with value ${options.largeArraySize}`)
     }
   }
 

test/array.test.js

@@ -529,3 +529,86 @@ buildTest({
   largeArraySize: 2e4,
   largeArrayMechanism: 'default'
 })
+
+test('error on invalid value for largeArraySize /1', (t) => {
+  t.plan(1)
+
+  t.throws(() => build({
+    title: 'large array of null values with default mechanism',
+    type: 'object',
+    properties: {
+      ids: {
+        type: 'array',
+        items: { type: 'null' }
+      }
+    }
+  }, {
+    largeArraySize: 'invalid'
+  }), Error('Unsupported large array size. Expected integer-like, got string with value invalid'))
+})
+
+test('error on invalid value for largeArraySize /2', (t) => {
+  t.plan(1)
+
+  t.throws(() => build({
+    title: 'large array of null values with default mechanism',
+    type: 'object',
+    properties: {
+      ids: {
+        type: 'array',
+        items: { type: 'null' }
+      }
+    }
+  }, {
+    largeArraySize: Infinity
+  }), Error('Unsupported large array size. Expected integer-like, got number with value Infinity'))
+})
+
+test('error on invalid value for largeArraySize /3', (t) => {
+  t.plan(1)
+
+  t.throws(() => build({
+    title: 'large array of null values with default mechanism',
+    type: 'object',
+    properties: {
+      ids: {
+        type: 'array',
+        items: { type: 'null' }
+      }
+    }
+  }, {
+    largeArraySize: [200]
+  }), Error('Unsupported large array size. Expected integer-like, got object with value 200'))
+})
+
+buildTest({
+  title: 'large array of integers with largeArraySize is bigint',
+  type: 'object',
+  properties: {
+    ids: {
+      type: 'array',
+      items: { type: 'integer' }
+    }
+  }
+}, {
+  ids: new Array(2e4).fill(42)
+}, {
+  largeArraySize: 20000n,
+  largeArrayMechanism: 'default'
+})
+
+buildTest({
+  title: 'large array of integers with largeArraySize is valid string',
+  type: 'object',
+  properties: {
+    ids: {
+      type: 'array',
+      items: { type: 'integer' }
+    }
+  }
+}, {
+  ids: new Array(1e4).fill(42)
+}, {
+  largeArraySize: '10000',
+  largeArrayMechanism: 'default'
+})

types/index.d.ts

@@ -169,6 +169,22 @@ declare namespace build {
      * Running mode of fast-json-stringify
      */
     mode?: 'debug' | 'standalone'
+
+    /**
+     * Large arrays are defined as arrays containing, by default, `20000`
+     * elements or more. That value can be adjusted via the option parameter
+     * `largeArraySize`.
+     *
+     * @default 20000
+     */
+    largeArraySize?: number | string | BigInt
+
+    /**
+     * Specify the function on how large Arrays should be stringified.
+     *
+     * @default 'default'
+     */
+    largeArrayMechanism?: 'default' | 'json-stringify'
   }
 
   export const validLargeArrayMechanisms: string[]

types/index.test-d.ts

@@ -217,3 +217,14 @@ const stringify7 = build({
 });
 stringify7(true);
 expectError(stringify7("a string"));
+
+// largeArrayMechanism
+
+build({}, { largeArrayMechanism: 'json-stringify'} )
+build({}, { largeArrayMechanism: 'default'} )
+expectError(build({} as Schema, { largeArrayMechanism: 'invalid'} ))
+
+build({}, { largeArraySize: 2000 } )
+build({}, { largeArraySize: '2e4' } )
+build({}, { largeArraySize: 2n } )
+expectError(build({} as Schema, { largeArraySize: ['asdf']} ))