Inspect

CHANGELOG.md

@@ -1,5 +1,18 @@
 # Changelog
 
+## [1.2.0]
+
+- Added new utility types to `Option` and `Result` types
+  - Option
+    - inspect(callback) -- Calls the provided `callback` if called on
+      a `Some` variant
+  - Result
+    - inspect(callback) -- Calls the provided `callback` if called on
+      a `Failure` variant
+    - expect(message) -- Unwraps the inner value if variant is `Success`,
+      otherwise throws an `Error` with the provided `message`
+- Update test structure to be more readable and easier to add tests
+
 ## [1.1.0]
 
 - Added new unsafe functions to the `Option` type to return unchecked values.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@dbidwell94/ts-utils",
-  "version": "1.1.0",
+  "version": "1.2.0",
   "description": "A collection of helpful TypeScript utilities with the aim of having limited production dependencies.",
   "main": "dist/index.js",
   "files": [

src/option/index.ts

@@ -77,6 +77,12 @@ export interface OptionUtils<T> {
    * @returns The value of the `Option<T>` if it is a `Some<T>`.
    */
   expect(message: string): T;
+  /**
+   * Peek into the inner value of this Option<T>, and if `isSome()` then the callback function will be run.
+   * @param callback the callback to run if this Option `isSome`
+   * @returns this `Option<T>`
+   */
+  inspect(callback: (value: T) => void): Option<T>;
   /**
    * Converts this `Option<T>` type into a `Result<T, E>` type. The `Result<T, E>` will be an `Err<E>` if the `Option<T>` is a `None`.
    * @param error The error to return if the `Option<T>` is a `None`.
@@ -146,6 +152,10 @@ function buildOption<T>(innerType: Some<T> | None): Option<T> {
       if (this.isSome()) return this.value;
       throw new OptionIsEmptyError(message);
     },
+    inspect(callback) {
+      if (this.isSome()) callback(this.value);
+      return this;
+    },
     okOr(error) {
       if (this.isNone()) {
         if (error instanceof Error) return result.err(error);