Merge 6d22b59 into 4e275a8

packages/kerosene-ui/package.json

@@ -22,7 +22,7 @@
   },
   "dependencies": {
     "@babel/runtime": "^7.10.4",
-    "@kablamo/kerosene": "^0.0.18",
+    "@kablamo/kerosene": "^0.0.19",
     "@types/lodash": "^4.14.157",
     "lodash": "^4.17.19"
   },

packages/kerosene/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@kablamo/kerosene",
-  "version": "0.0.18",
+  "version": "0.0.19",
   "repository": "https://github.com/KablamoOSS/kerosene/tree/master/packages/kerosene",
   "bugs": {
     "url": "https://github.com/KablamoOSS/kerosene/issues"

packages/kerosene/readme.md

@@ -240,6 +240,22 @@ From a union type `T`, allows properties which are not shared by all members to
 
 Removes the `readonly` modifier from all properties in `T`.
 
+### `Overloads<T>`
+
+From an overloaded function `T`, infer each overload as a tuple element.
+
+### `OverloadedParameters<T>`
+
+For an overloaded function `T`, infer the union of parameters for all overloads.
+
+### `OverloadedReturnType<T>`
+
+For an overloaded function `T`, infer the union of return types for all overloads.
+
+### `OverloadedReturnTypeWhen<T, P>`
+
+For an overloaded function `T`, infer the return type for the specific overload when parameters match `P`.
+
 ### `PickBy<T, TValue>`
 
 Creates a new type from `T` including only keys where the value is assignable to type `TValue`.

packages/kerosene/src/types/index.ts

@@ -79,6 +79,85 @@ export type MergedUnion<T extends object> = __MergedUnion__<T, T>;
  */
 export type Mutable<T> = { -readonly [P in keyof T]: T[P] };
 
+/**
+ * From an overloaded function `T`, infer each overload as a tuple element
+ */
+export type Overloads<T> = T extends {
+  (...args: infer P1): infer R1;
+  (...args: infer P2): infer R2;
+  (...args: infer P3): infer R3;
+  (...args: infer P4): infer R4;
+  (...args: infer P5): infer R5;
+  (...args: infer P6): infer R6;
+}
+  ? [
+      (...args: P1) => R1,
+      (...args: P2) => R2,
+      (...args: P3) => R3,
+      (...args: P4) => R4,
+      (...args: P5) => R5,
+      (...args: P6) => R6,
+    ]
+  : T extends {
+      (...args: infer P1): infer R1;
+      (...args: infer P2): infer R2;
+      (...args: infer P3): infer R3;
+      (...args: infer P4): infer R4;
+      (...args: infer P5): infer R5;
+    }
+  ? [
+      (...args: P1) => R1,
+      (...args: P2) => R2,
+      (...args: P3) => R3,
+      (...args: P4) => R4,
+      (...args: P5) => R5,
+    ]
+  : T extends {
+      (...args: infer P1): infer R1;
+      (...args: infer P2): infer R2;
+      (...args: infer P3): infer R3;
+      (...args: infer P4): infer R4;
+    }
+  ? [
+      (...args: P1) => R1,
+      (...args: P2) => R2,
+      (...args: P3) => R3,
+      (...args: P4) => R4,
+    ]
+  : T extends {
+      (...args: infer P1): infer R1;
+      (...args: infer P2): infer R2;
+      (...args: infer P3): infer R3;
+    }
+  ? [(...args: P1) => R1, (...args: P2) => R2, (...args: P3) => R3]
+  : T extends {
+      (...args: infer P1): infer R1;
+      (...args: infer P2): infer R2;
+    }
+  ? [(...args: P1) => R1, (...args: P2) => R2]
+  : T extends (...args: infer P1) => infer R1
+  ? [(...args: P1) => R1]
+  : never;
+
+/**
+ * For an overloaded function `T`, infer the union of parameters for all overloads
+ */
+export type OverloadedParameters<T> = Parameters<Overloads<T>[number]>;
+
+/**
+ * For an overloaded function `T`, infer the union of return types for all overloads
+ */
+export type OverloadedReturnType<T> = ReturnType<Overloads<T>[number]>;
+
+/**
+ * For an overloaded function `T`, infer the return type for the specific overload when parameters match `P`
+ */
+export type OverloadedReturnTypeWhen<T, P extends unknown[]> = T extends (
+  ...args: P
+) => infer R
+  ? R
+  : never;
+
 /**
  * Creates a new type from `T` including only keys where the value is assignable to type `TValue`
  */