commitlint: add OptionStatic.OfObj and .None

commitlint/fpHelpers.ts

@@ -16,11 +16,16 @@ export class None {
     public IsSome(): boolean {
         return false;
     }
+
+    /**
+     * @deprecated it is better to use `OptionStatic.None`
+     **/
+    constructor(){}
 }
 export class Some<T> {
     value: T;
 
-    constructor(val: T) {
+    constructor(val: NonNullable<T>) {
         this.value = val;
     }
 
@@ -32,4 +37,15 @@ export class Some<T> {
     }
 }
 
-export type Option<T> = (None | Some<T>) & IOption;
+export type Option<T> = (None | Some<NonNullable<T>>) & IOption;
+
+export class OptionStatic {
+    public static None = new None();
+    public static OfObj<T>(obj: T | null | undefined): Option<NonNullable<T>> {
+        if (obj === null || obj === undefined) {
+            return OptionStatic.None;
+        } else {
+            return new Some(obj);
+        }
+    }
+}

commitlint/tests/testHelpers.ts

@@ -1,5 +1,5 @@
 import { test, expect } from "vitest";
-import { None, Some, Option } from "../fpHelpers.js";
+import { None, Some, Option, OptionStatic } from "../fpHelpers.js";
 const { spawnSync } = require("child_process");
 const os = require("os");
 
@@ -12,6 +12,16 @@ function typeGuard(option: Option<number>) {
     }
 }
 
+function ofObj1(option: number | null): Option<number> {
+    let foo = OptionStatic.OfObj(option);
+    return foo;
+}
+
+function ofObj2(option: number | undefined): Option<number> {
+    let foo = OptionStatic.OfObj(option);
+    return foo;
+}
+
 test("testing Options", () => {
     let foo: Option<number> = new None();
     let bar: Option<number> = new Some(2);
@@ -20,14 +30,26 @@ test("testing Options", () => {
 });
 
 test("testing Is methods", () => {
-    let foo: Option<number> = new None();
+    let foo: Option<number> = OptionStatic.None;
     let bar: Option<number> = new Some(2);
     expect(foo.IsNone()).toBe(true);
     expect(bar.IsNone()).toBe(false);
     expect(foo.IsSome()).toBe(false);
     expect(bar.IsSome()).toBe(true);
 });
 
+test("testing OfObj", () => {
+    let two: number | null = 2;
+    expect(typeGuard(ofObj1(two))).toBe("4");
+    two = null;
+    expect(typeGuard(ofObj1(two))).toBe("NAH");
+
+    let four : number | undefined = 4;
+    expect(typeGuard(ofObj2(four))).toBe("16");
+    four = undefined;
+    expect(typeGuard(ofObj2(four))).toBe("NAH");
+});
+
 export function runCommitLintOnMsg(inputMsg: string) {
     // FIXME: should we .lowerCase().startsWith("win") in case it starts
     // returning Win64 in the future? thing is, our CI doesn't like this