Rename Omit to Except (#44)

Co-authored-by: Sindre Sorhus <sindresorhus@gmail.com>

index.d.ts

@@ -2,7 +2,7 @@
 export * from './source/basic';
 
 // Utilities
-export {Omit} from './source/omit';
+export {Except} from './source/except';
 export {Mutable} from './source/mutable';
 export {Merge} from './source/merge';
 export {MergeExclusive} from './source/merge-exclusive';

readme.md

@@ -36,14 +36,14 @@ $ npm install type-fest
 ## Usage
 
 ```ts
-import {Omit} from 'type-fest';
+import {Except} from 'type-fest';
 
 type Foo = {
 	unicorn: string;
 	rainbow: boolean;
 };
 
-type FooWithoutRainbow = Omit<Foo, 'rainbow'>;
+type FooWithoutRainbow = Except<Foo, 'rainbow'>;
 //=> {unicorn: string}
 ```
 
@@ -64,7 +64,7 @@ Click the type names for complete docs.
 
 ### Utilities
 
-- [`Omit`](source/omit.d.ts) - Create a type from an object type without certain keys.
+- [`Except`](source/except.d.ts) - Create a type from an object type without certain keys. This is a stricter version of [`Omit`](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-5.html#the-omit-helper-type).
 - [`Mutable`](source/mutable.d.ts) - Convert an object with `readonly` properties into a mutable object. Inverse of `Readonly<T>`.
 - [`Merge`](source/merge.d.ts) - Merge two types into a new type. Keys of the second type overrides keys of the first type.
 - [`MergeExclusive`](source/merge-exclusive.d.ts) - Create a type that has mutually exclusive properties.

source/except.d.ts

@@ -0,0 +1,22 @@
+/**
+Create a type from an object type without certain keys.
+
+This type is a stricter version of [`Omit`](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-5.html#the-omit-helper-type). The `Omit` type does not restrict the omitted keys to be keys present on the given type, while `Except` does. The benefits of a stricter type are avoiding typos and allowing the compiler to pick up on rename refactors automatically.
+
+Please upvote [this issue](https://github.com/microsoft/TypeScript/issues/30825) if you want to have the stricter version as a built-in in TypeScript.
+
+@example
+```
+import {Except} from 'type-fest';
+
+type Foo = {
+	a: number;
+	b: string;
+	c: boolean;
+};
+
+type FooWithoutA = Except<Foo, 'a' | 'c'>;
+//=> {b: string};
+```
+*/
+export type Except<ObjectType, KeysType extends keyof ObjectType> = Pick<ObjectType, Exclude<keyof ObjectType, KeysType>>;

source/merge.d.ts

@@ -1,4 +1,4 @@
-import {Omit} from './omit';
+import {Except} from './except';
 
 /**
 Merge two types into a new type. Keys of the second type overrides keys of the first type.
@@ -19,4 +19,4 @@ type Bar = {
 const ab: Merge<Foo, Bar> = {a: 1, b: 2};
 ```
 */
-export type Merge<FirstType, SecondType> = Omit<FirstType, Extract<keyof FirstType, keyof SecondType>> & SecondType;
+export type Merge<FirstType, SecondType> = Except<FirstType, Extract<keyof FirstType, keyof SecondType>> & SecondType;

source/require-at-least-one.d.ts

@@ -1,4 +1,4 @@
-import {Omit} from './omit';
+import {Except} from './except';
 
 /**
 Create a type that requires at least one of the given properties. The remaining properties are kept as is.
@@ -29,4 +29,4 @@ export type RequireAtLeastOne<ObjectType, KeysType extends keyof ObjectType = ke
 		)
 	}[KeysType]
 	// …then, make intersection types by adding the remaining properties to each mapped type.
-	& Omit<ObjectType, KeysType>;
+	& Except<ObjectType, KeysType>;

test-d/except.ts

@@ -0,0 +1,5 @@
+import {expectType} from 'tsd';
+import {Except} from '..';
+
+declare const except: Except<{a: number; b: string}, 'b'>;
+expectType<{a: number}>(except);