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author | Nayeem Rahman <nayeemrmn99@gmail.com> | 2020-05-09 13:34:47 +0100 |
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committer | GitHub <noreply@github.com> | 2020-05-09 08:34:47 -0400 |
commit | f184332c09c851faac50f598d29ebe4426e05464 (patch) | |
tree | 2659aba63702537fcde1bb64ddeafea1e5863f3e /std/_util/has_own_property.ts | |
parent | 2b02535028f868ea8dfc471c4921a237747ccd4a (diff) |
BREAKING(std): reorganization (#5087)
* Prepend underscores to private modules
* Remove collectUint8Arrays() It would be a misuse of Deno.iter()'s result.
* Move std/_util/async.ts to std/async
* Move std/util/sha*.ts to std/hash
Diffstat (limited to 'std/_util/has_own_property.ts')
-rw-r--r-- | std/_util/has_own_property.ts | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/std/_util/has_own_property.ts b/std/_util/has_own_property.ts new file mode 100644 index 000000000..351905cec --- /dev/null +++ b/std/_util/has_own_property.ts @@ -0,0 +1,30 @@ +// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license. + +/** + * Determines whether an object has a property with the specified name. + * Avoid calling prototype builtin `hasOwnProperty` for two reasons: + * + * 1. `hasOwnProperty` is defined on the object as something else: + * + * const options = { + * ending: 'utf8', + * hasOwnProperty: 'foo' + * }; + * options.hasOwnProperty('ending') // throws a TypeError + * + * 2. The object doesn't inherit from `Object.prototype`: + * + * const options = Object.create(null); + * options.ending = 'utf8'; + * options.hasOwnProperty('ending'); // throws a TypeError + * + * @param obj A Object. + * @param v A property name. + * @see https://eslint.org/docs/rules/no-prototype-builtins + */ +export function hasOwnProperty<T>(obj: T, v: PropertyKey): boolean { + if (obj == null) { + return false; + } + return Object.prototype.hasOwnProperty.call(obj, v); +} |