fix: improve useWireValue typing

forminator · Mar 29, 2020 · a4475a4 · a4475a4
1 parent 104fb97
commit a4475a4
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Showing 2 changed files with 27 additions and 37 deletions.
diff --git a/src/state-wire/use-wire-value.test.ts b/src/state-wire/use-wire-value.test.ts
@@ -18,7 +18,7 @@ describe('useWireValue', () => {
       describe('without initial value', () => {
         it('should return undefined', () => {
           const { result } = renderHook(() => {
-            const wire = useStateWire(null);
+            const wire = useStateWire<number>(null);
             const value = useWireValue(wire);
             return { value };
           });
@@ -42,7 +42,7 @@ describe('useWireValue', () => {
     describe('with initial  value on sibling', () => {
       it('should return wire initial value', () => {
         const { result } = renderHook(() => {
-          const parent = useStateWire(null);
+          const parent = useStateWire<number>(null);
           const wire = useStateWire(parent, 4);
           const value = useWireValue(wire);
           const sibling = useStateWire(parent, 5);
@@ -57,7 +57,7 @@ describe('useWireValue', () => {
     describe('with default value', () => {
       it('should returns default value', () => {
         const { result } = renderHook(() => {
-          const wire = useStateWire(null);
+          const wire = useStateWire<number>(null);
           const value = useWireValue(wire, 5);
           return { value };
         });

diff --git a/src/state-wire/use-wire-value.ts b/src/state-wire/use-wire-value.ts
@@ -1,40 +1,30 @@
 import { useDebugValue, useEffect, useState } from 'react';
+import { Defined } from '../utils/type-utils';
 import { useStabilityGuard } from '../utils/use-stability-guard';
-import { StateWire } from './state-wire';
+import { StateWire, WireState } from './state-wire';
 
-/**
- *
- * returns wire value and subscribe to wire for value updates
- *
- * @param wire
- *
- * @remarks
- * please always pass same wire param and avoid changing wire param. if wire argument changed, an error will be thrown.
- *
- */
-export function useWireValue<Value>(
-  wire: StateWire<Value> | null | undefined,
-): Value | undefined;
-/**
- *
- * returns wire value and subscribe to wire for value updates
- *
- * @param wire
- * @param defaultValue - return value if wire value is undefined
- *
- * @remarks
- *
- * please always pass same wire param and avoid changing wire param. if wire argument changed, an error will be thrown.
- *
- */
-export function useWireValue<Value>(
-  wire: StateWire<Value> | null | undefined,
-  defaultValue: Value,
-): Value | undefined;
-export function useWireValue<Value>(
-  wire: StateWire<Value> | null | undefined,
-  defaultValue?: Value,
-): Value | undefined {
+export function useWireValue(
+  wire: null | undefined,
+  defaultValue?: unknown,
+): undefined;
+export function useWireValue<W extends StateWire<any>>(wire: W): WireState<W>;
+export function useWireValue<W extends StateWire<any>>(
+  wire: W | null | undefined,
+  defaultValue: Defined<WireState<W>>,
+): Defined<WireState<W>>;
+export function useWireValue<W extends StateWire<any>>(
+  wire: W,
+  defaultValue?: WireState<W> | undefined,
+): WireState<W>;
+export function useWireValue<W extends StateWire<any>>(
+  wire: W | null | undefined,
+  defaultValue?: WireState<W>,
+): WireState<W> | undefined;
+export function useWireValue<W extends StateWire<any>>(
+  wire: W | null | undefined,
+  defaultValue?: WireState<W>,
+): WireState<W> | undefined {
+  type Value = WireState<W>;
   useStabilityGuard(wire);
   const wireValue = wire?.getValue();
   const valueToReturn = wireValue === undefined ? defaultValue : wireValue;