typescript-enum - npm Package Compare versions

Comparing version 1.3.0 to 1.4.0

README.md

+# typescript-enum
+
+A set of missing helpers to work with TypeScript enums with runtime and compile time safety. These helpers cover both string enums and numeric enums.
+
+### Installation
+
+```
+npm i typescript-enum
+```
+
+### Usage
+
+1) `enumValues` - converts an enum to iterable list:
+
+```ts
+import { enumValues } from 'typescript-enum'
+
+enum Color { R, G, B }
+
+console.log(enumValues(Color)) // [0, 1, 2]
+```
+
+2) `isEnumValid` - checks if value is a member of enum
+
+```ts
+import { enumValues } from 'typescript-enum'
+
+enum Color { R, G, B }
+
+const maybeColor = 0;
+const notColor = 999;
+console.log(isEnumValid(maybeColor, Color)); // true
+console.log(isEnumValid(notColor, Color)); // false
+
+if (isEnumValid(maybeColor)) {
+  // now the type of maybeColor is inferred to Color
+}
+
+```
+
+### Use cases
+
+#### 1. You have a list based on enum value. 
+
+❌ The following component should be updated whenever new member is added to enum
+```tsx 
+enum Permission { Read = 'r', Write = 'w', Edit = 'e' }
+
+const Component = () => {
+  return <List>
+    {[Permission.Read, Permission.Write, Permission.Edit].map(permission => {
+      // Render checkbox to edit permission
+    })}
+  </List>  
+}
+```
+
+✅ The following component doesn't need to be updated whenever new member is added to enum
+```tsx 
+import { enumValues } from 'typescript-enum'
+
+enum Permission { Read = 'r', Write = 'w', Edit = 'e' }
+
+const Component = () => {
+  return <List>
+    {enumValues(Permission).map(permission => {
+      // Render checkbox to edit permission
+    })}
+  </List>  
+}
+```
+
+#### 2. You want to make sure that unknown value is member of enum 
+
+❌ The following code requires hacky ways to check whether value is member of enum
+```tsx
+enum PackageType { Basic, Advanced, Premium }
+
+const packageInput: { type: number } = { type: 0 }
+
+function processPackage(packageType: PackageType) {
+  // ...  
+}
+
+processPackage(packageInput.type as any)
+```
+
+✅ The following code validates unknown value both runtime and compile type
+
+```tsx
+import { isEnumValid } from './isEnumValid'
+
+enum Package { Basic, Advanced, Premium }
+
+const packageInput: { type: number } = { type: 0 }
+
+function processPackage(packageType: PackageType) {
+  // ...  
+}
+
+if (!isEnumValid(packageInput.type)) {
+    throw new Error()
+}
+
+processPackage(packageInput.type)
+```
+
+As you see the type inference works correctly now, the type cast is no longer needed. You can even go further and use an assertion library:
+
+```tsx
+import { isEnumValid } from './isEnumValid'
+import { assert } from 'ts-essentials'
+
+enum Package { Basic, Advanced, Premium }
+
+const packageInput: { type: number } = { type: 0 }
+
+function processPackage(packageType: PackageType) {
+  // ...  
+}
+
+assert(isEnumValid(packageInput.type))
+processPackage(packageInput.type)
+```

dist/enumValues.d.ts

@@ -1,2 +0,2 @@
-import { EnumLike, EnumFiltered } from './types';
-export declare function enumValues<E extends EnumLike>(enumObject: E): EnumFiltered<E>[];
+import { EnumLike } from './types';
+export declare function enumValues<E extends EnumLike>(enumObject: E): E[keyof E][];

dist/types.d.ts

 export type EnumLike = {
     [key: string]: number | string;
 };
-export type EnumFiltered<E extends EnumLike> = E extends {
-    [key: string]: infer ET | string;
-} ? ET : never;

package.json

 {
   "name": "typescript-enum",
-  "version": "1.3.0",
+  "version": "1.4.0",
   "description": "TypeScript enum missed helpers",
@@ -5,0 +5,0 @@ "main": "dist/index.js",

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Found 1 instance in 1 package

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Total package byte prevSize

4184

172.93%

Number of package files

10

11.11%

Number of medium quality alerts

1

-50%

Number of lines in readme file

125

Infinity%

Worsened metrics

Lines of code

21

-12.5%

No dependency changes