Add tests for Number#toExponential (#664)

* Add tests for Number#toExponential

test/built-ins/Number/prototype/toExponential/infinity.js

@@ -0,0 +1,29 @@
+// Copyright (C) 2016 The V8 Project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+es6id: 20.1.3.2
+esid: sec-number.prototype.toexponential
+description: >
+  Return signed Infinity string if this is Infinity
+info: |
+  Number.prototype.toExponential ( fractionDigits )
+
+  1. Let x be ? thisNumberValue(this value).
+  [...]
+  5. Let s be the empty String.
+  6. If x < 0, then
+    a. Let s be "-".
+    b. Let x be -x.
+  7. If x = +∞, then
+    a. Return the concatenation of the Strings s and "Infinity".
+  [...]
+---*/
+
+assert.sameValue((+Infinity).toExponential(1000), "Infinity", "Infinity value");
+var n = new Number(+Infinity);
+assert.sameValue(n.toExponential(1000), "Infinity", "Number Infinity");
+
+assert.sameValue((-Infinity).toExponential(1000), "-Infinity", "-Infinity value");
+var n = new Number(-Infinity);
+assert.sameValue(n.toExponential(1000), "-Infinity", "Number -Infinity");

test/built-ins/Number/prototype/toExponential/nan.js

@@ -0,0 +1,22 @@
+// Copyright (C) 2016 The V8 Project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+es6id: 20.1.3.2
+esid: sec-number.prototype.toexponential
+description: >
+  Return "NaN" if this is NaN
+info: |
+  Number.prototype.toExponential ( fractionDigits )
+
+  1. Let x be ? thisNumberValue(this value).
+  2. Let f be ? ToInteger(fractionDigits).
+  3. Assert: f is 0, when fractionDigits is undefined.
+  4. If x is NaN, return the String "NaN".
+  [...]
+---*/
+
+assert.sameValue(NaN.toExponential(Infinity), "NaN", "NaN value");
+
+var n = new Number(NaN);
+assert.sameValue(n.toExponential(NaN), "NaN", "NaN obj");

test/built-ins/Number/prototype/toExponential/prop-desc.js

@@ -0,0 +1,18 @@
+// Copyright (C) 2016 The V8 Project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+es6id: 20.1.3.2
+esid: sec-number.prototype.toexponential
+description: >
+  "toExponential" property of Number.prototype
+info: >
+  ES6 section 17: Every other data property described in clauses 18 through 26
+  and in Annex B.2 has the attributes { [[Writable]]: true,
+  [[Enumerable]]: false, [[Configurable]]: true } unless otherwise specified.
+includes: [propertyHelper.js]
+---*/
+
+verifyNotEnumerable(Number.prototype, "toExponential");
+verifyWritable(Number.prototype, "toExponential");
+verifyConfigurable(Number.prototype, "toExponential");

test/built-ins/Number/prototype/toExponential/return-abrupt-tointeger-fractiondigits-symbol.js

@@ -0,0 +1,22 @@
+// Copyright (C) 2016 The V8 Project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+es6id: 20.1.3.2
+esid: sec-number.prototype.toexponential
+description: >
+  Return abrupt completion from ToInteger(symbol fractionDigits)
+info: |
+  Number.prototype.toExponential ( fractionDigits )
+
+  1. Let x be ? thisNumberValue(this value).
+  2. Let f be ? ToInteger(fractionDigits).
+  [...]
+features: [Symbol]
+---*/
+
+var fd = Symbol("1");
+
+assert.throws(TypeError, function() {
+  NaN.toExponential(fd);
+});

test/built-ins/Number/prototype/toExponential/return-abrupt-tointeger-fractiondigits.js

@@ -0,0 +1,35 @@
+// Copyright (C) 2016 The V8 Project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+es6id: 20.1.3.2
+esid: sec-number.prototype.toexponential
+description: >
+  Return abrupt completion from ToInteger(fractionDigits)
+info: |
+  Number.prototype.toExponential ( fractionDigits )
+
+  1. Let x be ? thisNumberValue(this value).
+  2. Let f be ? ToInteger(fractionDigits).
+  [...]
+---*/
+
+var fd1 = {
+  valueOf: function() {
+    throw new Test262Error();
+  }
+};
+
+var fd2 = {
+  toString: function() {
+    throw new Test262Error();
+  }
+};
+
+assert.throws(Test262Error, function() {
+  NaN.toExponential(fd1);
+}, "valueOf");
+
+assert.throws(Test262Error, function() {
+  NaN.toExponential(fd2);
+}, "toString");

test/built-ins/Number/prototype/toExponential/return-values.js

@@ -0,0 +1,53 @@
+// Copyright (C) 2016 The V8 Project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+es6id: 20.1.3.2
+esid: sec-number.prototype.toexponential
+description: >
+  Return regular string values
+---*/
+
+assert.sameValue((123.456).toExponential(0), "1e+2");
+assert.sameValue((123.456).toExponential(1), "1.2e+2");
+assert.sameValue((123.456).toExponential(2), "1.23e+2");
+assert.sameValue((123.456).toExponential(3), "1.235e+2");
+assert.sameValue((123.456).toExponential(4), "1.2346e+2");
+assert.sameValue((123.456).toExponential(5), "1.23456e+2");
+assert.sameValue((123.456).toExponential(6), "1.234560e+2");
+assert.sameValue((123.456).toExponential(7), "1.2345600e+2");
+assert.sameValue((123.456).toExponential(17), "1.23456000000000003e+2");
+assert.sameValue((123.456).toExponential(20), "1.23456000000000003070e+2");
+
+assert.sameValue((-123.456).toExponential(0), "-1e+2");
+assert.sameValue((-123.456).toExponential(1), "-1.2e+2");
+assert.sameValue((-123.456).toExponential(2), "-1.23e+2");
+assert.sameValue((-123.456).toExponential(3), "-1.235e+2");
+assert.sameValue((-123.456).toExponential(4), "-1.2346e+2");
+assert.sameValue((-123.456).toExponential(5), "-1.23456e+2");
+assert.sameValue((-123.456).toExponential(6), "-1.234560e+2");
+assert.sameValue((-123.456).toExponential(7), "-1.2345600e+2");
+assert.sameValue((-123.456).toExponential(17), "-1.23456000000000003e+2");
+assert.sameValue((-123.456).toExponential(20), "-1.23456000000000003070e+2");
+
+assert.sameValue((0.0001).toExponential(0), "1e-4");
+assert.sameValue((0.0001).toExponential(1), "1.0e-4");
+assert.sameValue((0.0001).toExponential(2), "1.00e-4");
+assert.sameValue((0.0001).toExponential(3), "1.000e-4");
+assert.sameValue((0.0001).toExponential(4), "1.0000e-4");
+assert.sameValue((0.0001).toExponential(16), "1.0000000000000000e-4");
+assert.sameValue((0.0001).toExponential(17), "1.00000000000000005e-4");
+assert.sameValue((0.0001).toExponential(18), "1.000000000000000048e-4");
+assert.sameValue((0.0001).toExponential(19), "1.0000000000000000479e-4");
+assert.sameValue((0.0001).toExponential(20), "1.00000000000000004792e-4");
+
+assert.sameValue((0.9999).toExponential(0), "1e+0");
+assert.sameValue((0.9999).toExponential(1), "1.0e+0");
+assert.sameValue((0.9999).toExponential(2), "1.00e+0");
+assert.sameValue((0.9999).toExponential(3), "9.999e-1");
+assert.sameValue((0.9999).toExponential(4), "9.9990e-1");
+assert.sameValue((0.9999).toExponential(16), "9.9990000000000001e-1");
+assert.sameValue((0.9999).toExponential(17), "9.99900000000000011e-1");
+assert.sameValue((0.9999).toExponential(18), "9.999000000000000110e-1");
+assert.sameValue((0.9999).toExponential(19), "9.9990000000000001101e-1");
+assert.sameValue((0.9999).toExponential(20), "9.99900000000000011013e-1");

test/built-ins/Number/prototype/toExponential/this-is-0-fractiondigits-is-0.js

@@ -0,0 +1,35 @@
+// Copyright (C) 2016 The V8 Project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+es6id: 20.1.3.2
+esid: sec-number.prototype.toexponential
+description: >
+  Return "0" if this value is 0 and ToInteger(fractionDigits) is 0
+info: |
+  Number.prototype.toExponential ( fractionDigits )
+
+  1. Let x be ? thisNumberValue(this value).
+  [...]
+  9. If x = 0, then
+    a. Let m be the String consisting of f+1 occurrences of the code unit 0x0030
+    (DIGIT ZERO).
+    b. Let e be 0.
+  [...]
+  11. If f ≠ 0, then
+    [...]
+  12. If e = 0, then
+    a. Let c be "+".
+    b. Let d be "0".
+  [...]
+  14. Let m be the concatenation of the four Strings m, "e", c, and d.
+  15. Return the concatenation of the Strings s and m. 
+---*/
+
+assert.sameValue(Number.prototype.toExponential(0), "0e+0", "Number.prototype");
+
+assert.sameValue((0).toExponential(0), "0e+0", "(0).toExponential(0)");
+assert.sameValue((-0).toExponential(0), "0e+0", "(-0).toExponential(0)");
+
+assert.sameValue((0).toExponential(-0), "0e+0", "(0).toExponential(-0)");
+assert.sameValue((-0).toExponential(-0), "0e+0", "(-0).toExponential(-0)");

test/built-ins/Number/prototype/toExponential/this-is-0-fractiondigits-is-not-0.js

@@ -0,0 +1,41 @@
+// Copyright (C) 2016 The V8 Project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+es6id: 20.1.3.2
+esid: sec-number.prototype.toexponential
+description: >
+  Return string value for this value = 0 and fractionDigits != 0
+info: |
+  Number.prototype.toExponential ( fractionDigits )
+
+  1. Let x be ? thisNumberValue(this value).
+  [...]
+  9. If x = 0, then
+    a. Let m be the String consisting of f+1 occurrences of the code unit 0x0030
+    (DIGIT ZERO).
+    b. Let e be 0.
+  [...]
+  11. If f ≠ 0, then
+    a. Let a be the first element of m, and let b be the remaining f elements of m.
+    b. Let m be the concatenation of the three Strings a, ".", and b.
+  12. If e = 0, then
+    a. Let c be "+".
+    b. Let d be "0".
+  [...]
+  14. Let m be the concatenation of the four Strings m, "e", c, and d.
+  15. Return the concatenation of the Strings s and m. 
+---*/
+
+assert.sameValue((0).toExponential(1), "0.0e+0", "0 and 1");
+assert.sameValue((0).toExponential(2), "0.00e+0", "0 and 2");
+assert.sameValue((0).toExponential(7), "0.0000000e+0", "0 and 7");
+assert.sameValue((0).toExponential(20), "0.00000000000000000000e+0", "0 and 20");
+
+assert.sameValue((-0).toExponential(1), "0.0e+0", "-0 and 1");
+assert.sameValue((-0).toExponential(2), "0.00e+0", "-0 and 2");
+assert.sameValue((-0).toExponential(7), "0.0000000e+0", "-0 and 7");
+assert.sameValue((-0).toExponential(20), "0.00000000000000000000e+0", "-0 and 20");
+
+assert.sameValue((0.0).toExponential(4), "0.0000e+0", "0.0 and 4");
+assert.sameValue((-0.0).toExponential(4), "0.0000e+0", "-0.0 and 4");

test/built-ins/Number/prototype/toExponential/this-type-not-number-or-number-object.js

@@ -0,0 +1,68 @@
+// Copyright (C) 2016 The V8 Project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+es6id: 20.1.3.2
+esid: sec-number.prototype.toexponential
+description: >
+  Throws a TypeError if this value is not a number object or value
+info: |
+  20.1.3 Properties of the Number Prototype Object
+
+  The Number prototype object is the intrinsic object %NumberPrototype%. The
+  Number prototype object is an ordinary object. The Number prototype is itself
+  a Number object; it has a [[NumberData]] internal slot with the value +0.
+
+  [...]
+  The abstract operation thisNumberValue(value) performs the following steps:
+
+  1. If Type(value) is Number, return value.
+  2. If Type(value) is Object and value has a [[NumberData]] internal slot, then
+    a. Assert: value's [[NumberData]] internal slot is a Number value.
+    b. Return the value of value's [[NumberData]] internal slot.
+  3. Throw a TypeError exception.
+
+  Number.prototype.toExponential ( fractionDigits )
+
+  1. Let x be ? thisNumberValue(this value).
+  [...]
+features: [Symbol]
+---*/
+
+var toExponential = Number.prototype.toExponential;
+
+assert.throws(TypeError, function() {
+  toExponential.call({}, 1);
+}, "{}");
+
+assert.throws(TypeError, function() {
+  toExponential.call("1", 1);
+}, "string");
+
+assert.throws(TypeError, function() {
+  toExponential.call(Number, 1);
+}, "Number");
+
+assert.throws(TypeError, function() {
+  toExponential.call(true, 1);
+}, "true");
+
+assert.throws(TypeError, function() {
+  toExponential.call(false, 1);
+}, "false");
+
+assert.throws(TypeError, function() {
+  toExponential.call(null, 1);
+}, "null");
+
+assert.throws(TypeError, function() {
+  toExponential.call(undefined, 1);
+}, "undefined");
+
+assert.throws(TypeError, function() {
+  toExponential.call(Symbol("1"), 1);
+}, "symbol");
+
+assert.throws(TypeError, function() {
+  toExponential.call([], 1);
+}, "[]");

test/built-ins/Number/prototype/toExponential/tointeger-fractiondigits.js

@@ -0,0 +1,35 @@
+// Copyright (C) 2016 The V8 Project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+es6id: 20.1.3.2
+esid: sec-number.prototype.toexponential
+description: >
+  ToInteger(fractionDigits operations)
+info: |
+  Number.prototype.toExponential ( fractionDigits )
+
+  1. Let x be ? thisNumberValue(this value).
+  2. Let f be ? ToInteger(fractionDigits).
+  [...]
+---*/
+
+assert.sameValue((123.456).toExponential(0.1), "1e+2", "0.1");
+assert.sameValue((123.456).toExponential(-0.1), "1e+2", "-0.1");
+assert.sameValue((123.456).toExponential(0.9), "1e+2", "0.9");
+assert.sameValue((123.456).toExponential(-0.9), "1e+2", "-0.9");
+
+assert.sameValue((123.456).toExponential(false), "1e+2", "false");
+assert.sameValue((123.456).toExponential(true), "1.2e+2", "true");
+
+assert.sameValue((123.456).toExponential(NaN), "1e+2", "NaN");
+assert.sameValue((123.456).toExponential(null), "1e+2", "null");
+
+assert.sameValue((123.456).toExponential("2"), "1.23e+2", "string");
+assert.sameValue((123.456).toExponential(""), "1e+2", "the empty string");
+
+assert.sameValue((123.456).toExponential([]), "1e+2", "[]");
+assert.sameValue((123.456).toExponential([2]), "1.23e+2", "[2]");
+
+assert.sameValue((0).toExponential(undefined), "0e+0", "undefined");
+assert.sameValue((0).toExponential(), "0e+0", "no arg");

test/built-ins/Number/prototype/toExponential/undefined-fractiondigits.js

@@ -0,0 +1,39 @@
+// Copyright (C) 2016 The V8 Project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+es6id: 20.1.3.2
+esid: sec-number.prototype.toexponential
+description: >
+  Handle undefined fractionDigits, not only casting it to 0
+info: |
+  Number.prototype.toExponential ( fractionDigits )
+
+  1. Let x be ? thisNumberValue(this value).
+  2. Let f be ? ToInteger(fractionDigits).
+  [...]
+  10. Else x ≠ 0,
+    a. If fractionDigits is not undefined, then
+      i. Let e and n be integers such that 10f ≤ n < 10f+1 and for which the
+         exact mathematical value of n × 10e-f - x is as close to zero as
+         possible. If there are two such sets of e and n, pick the e and n for
+         which n × 10e-f is larger.
+    b. Else fractionDigits is undefined,
+      i. Let e, n, and f be integers such that f ≥ 0, 10f ≤ n < 10f+1, the
+         Number value for n × 10e-f is x, and f is as small as possible. Note
+         that the decimal representation of n has f+1 digits, n is not divisible
+         by 10, and the least significant digit of n is not necessarily uniquely
+         determined by these criteria.
+---*/
+
+assert.sameValue((123.456).toExponential(undefined), "1.23456e+2", "undefined");
+assert.sameValue((123.456).toExponential(), "1.23456e+2", "no arg");
+assert.sameValue((123.456).toExponential(0), "1e+2", "0");
+
+assert.sameValue((1.1e-32).toExponential(undefined), "1.1e-32", "undefined");
+assert.sameValue((1.1e-32).toExponential(), "1.1e-32", "no arg");
+assert.sameValue((1.1e-32).toExponential(0), "1e-32", "0");
+
+assert.sameValue((100).toExponential(undefined), "1e+2", "undefined");
+assert.sameValue((100).toExponential(), "1e+2", "no arg");
+assert.sameValue((100).toExponential(0), "1e+2", "0");