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Infinity and early conditions #11

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2158d0e
upgrade to mocha v8
customcommander Apr 16, 2021
945a312
add test to make sure numbers arent rounded
customcommander Apr 16, 2021
c822009
add test for negative numbers
customcommander Apr 16, 2021
d22fda2
use const vs var in tests
customcommander Apr 16, 2021
9542213
early exit condition when string is empty
customcommander Apr 16, 2021
fd4f86a
throws when attempting to repeat ad infinitum
customcommander Apr 16, 2021
0e41e0d
test against latest stable node.js version
customcommander Apr 16, 2021
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4 changes: 0 additions & 4 deletions .travis.yml
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Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,3 @@ os:
language: node_js
node_js:
- node
- '6'
- '4'
- '0.12'
- '0.10'
8 changes: 8 additions & 0 deletions index.js
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Original file line number Diff line number Diff line change
Expand Up @@ -43,11 +43,19 @@ function repeat(str, num) {
throw new TypeError('expected a string');
}

// no need to repeat an empty string
if (str === '') return '';

// cover common, quick use cases
if (num === 1) return str;
if (num === 2) return str + str;

var max = str.length * num;

if (max === Infinity) {
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Nice work. Please move this check to be just after the string check (line 46 or so) and change it to if (num === Infinity).

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@customcommander customcommander Apr 20, 2021 •
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The reason I put it on that line was to leverage the implicit "parseFloat()" when str.length and num are multiplied together e.g.

5 * Infinity;
//=> Infinity

5 * 'Infinity';
//=> Infinity

5 * '    Infinity   ';
//=> Infinity

That was also motivated by some of the tests that seem to suggest that num can be given as a string too. I'm happy to make the change but should I still care about the case of Infinity as a string then?

By the way it seems that if num can be given as a string then the two shortcuts at L50,51 are most likely ignored. Should this be addressed?

throw new TypeError('cannot repeat indefinitely');
}

if (cache !== str || typeof cache === 'undefined') {
cache = str;
res = '';
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4 changes: 2 additions & 2 deletions package.json
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Expand Up @@ -31,7 +31,7 @@
"benchmarked": "^0.2.5",
"gulp-format-md": "^0.1.11",
"isobject": "^2.1.0",
"mocha": "^3.1.2",
"mocha": "^8.3.2",
"repeating": "^3.0.0",
"text-table": "^0.2.0",
"yargs-parser": "^4.0.2"
Expand Down Expand Up @@ -74,4 +74,4 @@
"verb"
]
}
}
}
24 changes: 22 additions & 2 deletions test.js
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Original file line number Diff line number Diff line change
Expand Up @@ -8,8 +8,9 @@
'use strict';

require('mocha');
var assert = require('assert');
var repeat = require('./');
const assert = require('assert');
const { it } = require('mocha');
const repeat = require('./');

describe('repeat', function() {
it('should return an empty string when a number is not given:', function() {
Expand All @@ -23,6 +24,18 @@ describe('repeat', function() {
assert.equal(repeat('a', null), '');
});

it('shoud not round numbers:', function() {
assert.equal(repeat('A', 6.9), repeat('A', 6));
assert.equal(repeat('A', '6.9'), repeat('A', 6));
});

it('should return an empty string for negative numbers:', function () {
assert.equal(repeat('A', -42), '');
assert.equal(repeat('A', '-42'), '');
assert.equal(repeat('A', -Infinity), '');
assert.equal(repeat('A', '-Infinity'), '');
});

it('should repeat the given string n times', function() {
assert.equal(repeat(' ', 0), '');
assert.equal(repeat('a', 0), '');
Expand Down Expand Up @@ -59,4 +72,11 @@ describe('repeat', function() {
assert.throws(function() {repeat(10); }, /expected a string/);
assert.throws(function() {repeat(null); }, /expected a string/);
});

it('should throw an error when attempting to repeat ad infinitum', function () {
assert.throws(function () { repeat('foo', Infinity); });
assert.throws(function () { repeat('foo', 'Infinity'); });
assert.doesNotThrow(function () { repeat('foo', -Infinity); });
assert.doesNotThrow(function () { repeat('foo', '-Infinity'); });
});
});