🎉 Add custom inspect function for Node.js >= 10.12.0

index.js

@@ -81,4 +81,16 @@ Object.defineProperty(ImageData.prototype, 'height', {
   get () { return heightMap.get(this) }
 })
 
+Object.defineProperty(ImageData.prototype, Symbol.for('nodejs.util.inspect.custom'), {
+  enumerable: false,
+  configurable: true,
+  value: function inspectImageData (depth, options) {
+    if (depth < 0) {
+      return options.stylize('[ImageData]', 'special')
+    }
+
+    return Object.assign(new (class ImageData {})(), { data: this.data, width: this.width, height: this.height }, this)
+  }
+})
+
 module.exports = ImageData

test.js

@@ -200,3 +200,52 @@ assert(ImageData.length === 2)
   assert(img.height === 16)
   assert(img.data === arr1)
 }
+
+{
+  const img = new ImageData(1, 1)
+
+  const keys = Object.keys(img)
+  assert(keys.length === 1)
+  assert(keys[0] === 'data')
+
+  const ownPropertyNames = Object.getOwnPropertyNames(img)
+  assert(ownPropertyNames.length === 1)
+  assert(ownPropertyNames[0] === 'data')
+
+  const enumerableKeys = []
+  for (const key in img) enumerableKeys.push(key)
+  assert(enumerableKeys.length === 3)
+  assert(enumerableKeys.includes('data'))
+  assert(enumerableKeys.includes('width'))
+  assert(enumerableKeys.includes('height'))
+}
+
+// Node.js 10.12.0 and newer
+if (typeof process === 'object' && require('util').inspect.custom === Symbol.for('nodejs.util.inspect.custom')) {
+  const { inspect } = require('util')
+  const img = new ImageData(1, 1)
+
+  assert(inspect(img, { colors: false, depth: -1 }) === '[ImageData]')
+  assert(inspect(img, { colors: true, depth: -1 }) === '\u001b[36m[ImageData]\u001b[39m')
+
+  assert(inspect(img, { colors: false, depth: 0 }) === 'ImageData { data: [Uint8ClampedArray], width: 1, height: 1 }')
+  assert(inspect(img, { colors: true, depth: 0 }) === 'ImageData { data: \u001b[36m[Uint8ClampedArray]\u001b[39m, width: \u001b[33m1\u001b[39m, height: \u001b[33m1\u001b[39m }')
+
+  if (/^v(12|[2-9]\d+)\./.test(process.version)) {
+    assert(inspect(img, { colors: false, depth: 1 }) === 'ImageData {\n  data: Uint8ClampedArray [ 0, 0, 0, 0 ],\n  width: 1,\n  height: 1\n}')
+    assert(inspect(img, { colors: true, depth: 1 }) === 'ImageData {\n  data: Uint8ClampedArray [ \u001b[33m0\u001b[39m, \u001b[33m0\u001b[39m, \u001b[33m0\u001b[39m, \u001b[33m0\u001b[39m ],\n  width: \u001b[33m1\u001b[39m,\n  height: \u001b[33m1\u001b[39m\n}')
+  } else {
+    assert(inspect(img, { colors: false, depth: 1 }) === 'ImageData { data: Uint8ClampedArray [ 0, 0, 0, 0 ], width: 1, height: 1 }')
+    assert(inspect(img, { colors: true, depth: 1 }) === 'ImageData { data: Uint8ClampedArray [ \u001b[33m0\u001b[39m, \u001b[33m0\u001b[39m, \u001b[33m0\u001b[39m, \u001b[33m0\u001b[39m ], width: \u001b[33m1\u001b[39m, height: \u001b[33m1\u001b[39m }')
+  }
+
+  img.test = 'foobar'
+
+  if (/^v(12|[2-9]\d+)\./.test(process.version)) {
+    assert(inspect(img, { colors: false, depth: 1 }) === 'ImageData {\n  data: Uint8ClampedArray [ 0, 0, 0, 0 ],\n  width: 1,\n  height: 1,\n  test: \'foobar\'\n}')
+    assert(inspect(img, { colors: true, depth: 1 }) === 'ImageData {\n  data: Uint8ClampedArray [ \u001b[33m0\u001b[39m, \u001b[33m0\u001b[39m, \u001b[33m0\u001b[39m, \u001b[33m0\u001b[39m ],\n  width: \u001b[33m1\u001b[39m,\n  height: \u001b[33m1\u001b[39m,\n  test: \u001b[32m\'foobar\'\u001b[39m\n}')
+  } else {
+    assert(inspect(img, { colors: false, depth: 1 }) === 'ImageData {\n  data: Uint8ClampedArray [ 0, 0, 0, 0 ],\n  width: 1,\n  height: 1,\n  test: \'foobar\' }')
+    assert(inspect(img, { colors: true, depth: 1 }) === 'ImageData {\n  data: Uint8ClampedArray [ \u001b[33m0\u001b[39m, \u001b[33m0\u001b[39m, \u001b[33m0\u001b[39m, \u001b[33m0\u001b[39m ],\n  width: \u001b[33m1\u001b[39m,\n  height: \u001b[33m1\u001b[39m,\n  test: \u001b[32m\'foobar\'\u001b[39m }')
+  }
+}