test: Write tests for Number class

The new tests cover a part of the basic type conversion from JavaScript
type to native type.

PR-URL: nodejs/node-addon-api#195
Reviewed-By: Michael Dawson <[email protected]>

test/basic_types/number.cc

@@ -0,0 +1,57 @@
+#include <cfloat>
+
+#include "napi.h"
+
+using namespace Napi;
+
+Value ToInt32(const CallbackInfo& info) {
+  return Number::New(info.Env(), info[0].As<Number>().Int32Value());
+}
+
+Value ToUint32(const CallbackInfo& info) {
+  return Number::New(info.Env(), info[0].As<Number>().Uint32Value());
+}
+
+Value ToInt64(const CallbackInfo& info) {
+  return Number::New(info.Env(), info[0].As<Number>().Int64Value());
+}
+
+Value ToFloat(const CallbackInfo& info) {
+  return Number::New(info.Env(), info[0].As<Number>().FloatValue());
+}
+
+Value ToDouble(const CallbackInfo& info) {
+  return Number::New(info.Env(), info[0].As<Number>().DoubleValue());
+}
+
+Value MinFloat(const CallbackInfo& info) {
+  return Number::New(info.Env(), FLT_MIN);
+}
+
+Value MaxFloat(const CallbackInfo& info) {
+  return Number::New(info.Env(), FLT_MAX);
+}
+
+Value MinDouble(const CallbackInfo& info) {
+  return Number::New(info.Env(), DBL_MIN);
+}
+
+Value MaxDouble(const CallbackInfo& info) {
+  return Number::New(info.Env(), DBL_MAX);
+}
+
+Object InitBasicTypesNumber(Env env) {
+  Object exports = Object::New(env);
+
+  exports["toInt32"] = Function::New(env, ToInt32);
+  exports["toUint32"] = Function::New(env, ToUint32);
+  exports["toInt64"] = Function::New(env, ToInt64);
+  exports["toFloat"] = Function::New(env, ToFloat);
+  exports["toDouble"] = Function::New(env, ToDouble);
+  exports["minFloat"] = Function::New(env, MinFloat);
+  exports["maxFloat"] = Function::New(env, MaxFloat);
+  exports["minDouble"] = Function::New(env, MinDouble);
+  exports["maxDouble"] = Function::New(env, MaxDouble);
+
+  return exports;
+}

test/basic_types/number.js

@@ -0,0 +1,83 @@
+'use strict';
+
+const buildType = process.config.target_defaults.default_configuration;
+const assert = require('assert');
+
+test(require(`../build/${buildType}/binding.node`));
+test(require(`../build/${buildType}/binding_noexcept.node`));
+
+function test(binding) {
+  const MIN_INT32 = -2147483648;
+  const MAX_INT32 = 2147483647;
+  const MIN_UINT32 = 0;
+  const MAX_UINT32 = 4294967295;
+  const MIN_INT64 = Number.MIN_SAFE_INTEGER;
+  const MAX_INT64 = Number.MAX_SAFE_INTEGER;
+  const MIN_FLOAT = binding.basic_types_number.minFloat();
+  const MAX_FLOAT = binding.basic_types_number.maxFloat();
+  const MIN_DOUBLE = binding.basic_types_number.minDouble();
+  const MAX_DOUBLE = binding.basic_types_number.maxDouble();
+
+  function randomRangeTestForInteger(min, max, converter) {
+    for (let i = min; i < max; i+= Math.floor(Math.random() * max / 100)) {
+        assert.strictEqual(i, converter(i));
+    }
+  }
+
+  // Test for 32bit signed integer [-2147483648, 2147483647]
+  {
+    // Range tests
+    randomRangeTestForInteger(MIN_INT32, MAX_INT32, binding.basic_types_number.toInt32);
+    assert.strictEqual(MIN_INT32, binding.basic_types_number.toInt32(MIN_INT32));
+    assert.strictEqual(MAX_INT32, binding.basic_types_number.toInt32(MAX_INT32));
+
+    // Overflow tests
+    assert.notStrictEqual(MAX_INT32 + 1, binding.basic_types_number.toInt32(MAX_INT32 + 1));
+    assert.notStrictEqual(MIN_INT32 - 1, binding.basic_types_number.toInt32(MIN_INT32 - 1));
+  }
+
+  // Test for 32bit unsigned integer [0, 4294967295]
+  {
+    // Range tests
+    randomRangeTestForInteger(MIN_UINT32, MAX_UINT32, binding.basic_types_number.toUint32);
+    assert.strictEqual(MIN_UINT32, binding.basic_types_number.toUint32(MIN_UINT32));
+    assert.strictEqual(MAX_UINT32, binding.basic_types_number.toUint32(MAX_UINT32));
+
+    // Overflow tests
+    assert.notStrictEqual(MAX_UINT32 + 1, binding.basic_types_number.toUint32(MAX_UINT32 + 1));
+    assert.notStrictEqual(MIN_UINT32 - 1, binding.basic_types_number.toUint32(MIN_UINT32 - 1));
+  }
+
+  // Test for 64bit signed integer
+  {
+    // Range tests
+    randomRangeTestForInteger(MIN_INT64, MAX_INT64, binding.basic_types_number.toInt64);
+    assert.strictEqual(MIN_INT64, binding.basic_types_number.toInt64(MIN_INT64));
+    assert.strictEqual(MAX_INT64, binding.basic_types_number.toInt64(MAX_INT64));
+
+    // The int64 type can't be represented with full precision in JavaScript.
+    // So, we are not able to do overflow test here.
+    // Please see https://tc39.github.io/ecma262/#sec-ecmascript-language-types-number-type.
+  }
+
+  // Test for float type (might be single-precision 32bit IEEE 754 floating point number)
+  {
+    // Range test
+    assert.strictEqual(MIN_FLOAT, binding.basic_types_number.toFloat(MIN_FLOAT));
+    assert.strictEqual(MAX_FLOAT, binding.basic_types_number.toFloat(MAX_FLOAT));
+
+    // Overflow test
+    assert.strictEqual(0, binding.basic_types_number.toFloat(MIN_FLOAT * MIN_FLOAT));
+    assert.strictEqual(Infinity, binding.basic_types_number.toFloat(MAX_FLOAT * MAX_FLOAT));
+  }
+
+  // Test for double type (is double-precision 64 bit IEEE 754 floating point number)
+  {
+    assert.strictEqual(MIN_DOUBLE, binding.basic_types_number.toDouble(MIN_DOUBLE));
+    assert.strictEqual(MAX_DOUBLE, binding.basic_types_number.toDouble(MAX_DOUBLE));
+
+    // Overflow test
+    assert.strictEqual(0, binding.basic_types_number.toDouble(MIN_DOUBLE * MIN_DOUBLE));
+    assert.strictEqual(Infinity, binding.basic_types_number.toDouble(MAX_DOUBLE * MAX_DOUBLE));
+  }
+}

test/binding.cc

@@ -4,6 +4,7 @@ using namespace Napi;
 
 Object InitArrayBuffer(Env env);
 Object InitAsyncWorker(Env env);
+Object InitBasicTypesNumber(Env env);
 Object InitBuffer(Env env);
 Object InitError(Env env);
 Object InitExternal(Env env);
@@ -17,6 +18,7 @@ Object InitObjectWrap(Env env);
 Object Init(Env env, Object exports) {
   exports.Set("arraybuffer", InitArrayBuffer(env));
   exports.Set("asyncworker", InitAsyncWorker(env));
+  exports.Set("basic_types_number", InitBasicTypesNumber(env));
   exports.Set("buffer", InitBuffer(env));
   exports.Set("error", InitError(env));
   exports.Set("external", InitExternal(env));

test/binding.gyp

@@ -3,6 +3,7 @@
     'sources': [
         'arraybuffer.cc',
         'asyncworker.cc',
+        'basic_types/number.cc',
         'binding.cc',
         'buffer.cc',
         'error.cc',

test/index.js

@@ -10,6 +10,7 @@ process.config.target_defaults.default_configuration =
 let testModules = [
   'arraybuffer',
   'asyncworker',
+  'basic_types/number',
   'buffer',
   'error',
   'external',