add screenshots and images for docs. add icon.

lib/__tests__/dimensions-test.ts

@@ -0,0 +1,14 @@
+import { diameterToLength, length_t } from '../dimensions';
+
+describe('diameterToLength', () => {
+    it('should throw an error if the units of the outer and inner diameters do not match', () => {
+        expect(() => diameterToLength({ l: 10, u: 'inch' }, { l: 8, u: 'foot' }, 2)).toThrow('diameter units must match!');
+    });
+
+    it('should return the correct length for multiple rings with different units', () => {
+        const outer : length_t = {l: 25, u: "in"};
+        const inner: length_t = {l : 1, u: "in"};
+        const l = diameterToLength(outer, inner, 12);
+        expect(l.l).toBeCloseTo(490, -1.0);
+    });
+});

lib/dimensions.ts

@@ -0,0 +1,52 @@
+import convert from "convert";
+import { Length } from "convert";
+
+export type length_t = {
+    l: number; u: Length;
+};
+
+export type area_t = length_t & {
+    w: number;
+};
+
+export type dimensions_t = area_t | length_t;
+
+export type product_type_t = "area" | "length";
+
+export const isArea = (d: dimensions_t) => ("width" in d);
+export const isLength = (d: dimensions_t) => (!("width" in d));
+export const dimensionType = (d: dimensions_t) => isArea(d) ? "area" : "length"; export function matchDimensions(d1: dimensions_t, d2: dimensions_t) {
+    if (!(
+        (isArea(d1) && isArea(d2)) ||
+        (isLength(d1) && isLength(d2))
+    )) {
+        throw new Error(`Dimension mismatch: ${JSON.stringify(d1)} / ${JSON.stringify(d1)}`);
+    }
+
+    return {
+        l: convert(d1.l, d1.u).to(d2.u),
+        u: d2.u,
+        ...(
+            "w" in d1 ?
+                { w: convert(d1.w, d1.u).to(d2.u), }
+                : {}
+        )
+    };
+}
+
+/**
+ * Gets the total length of a carpet roll based on a diameter
+ * @param outerDiameter Outer diameter of the carpet roll
+ * @param innerDiameter Inner diameter of the carpet roll (the "hole")
+ * @param numRings Number of "rings" or "layers,"" just like a tree 🙂 🌲
+ */
+export function diameterToLength(outerDiameter: length_t, innerDiameter: length_t, numRings: number) {
+    if (outerDiameter.u !== innerDiameter.u) {
+        throw new Error("diameter units must match!")
+    }
+    const thickness = (((outerDiameter.l - innerDiameter.l) / 2) / numRings);
+    return {
+        l: Math.PI * (Math.pow(outerDiameter.l, 2) / 4) - (Math.pow(innerDiameter.l, 2) / 4) / thickness,
+        u: innerDiameter.u,
+    };
+}

lib/product.ts

@@ -1,6 +1,8 @@
 import uuid from "react-native-uuid";
-import convert, { Area, Length } from "convert";
+import { Area } from "convert";
 import { Transform } from "class-transformer";
+import { dimensions_t, area_t } from "./dimensions";
+import { matchDimensions } from "./dimensions";
 
 export type Id = string;
 
@@ -15,55 +17,18 @@ export type ProductAttributes = {
     currency?: Currency,
     // [index:string]: any,
 }
-export type length_t = {
-    l: number, u: Length
-}
-
-export type area_t = length_t & {
-    w: number,
-}
-
-export type dimensions_t = area_t | length_t;
-
-export type ProductData = {
-    id?: Id,
-    pricePerUnit: number,
-    dimensions: dimensions_t,
-    attributes?: ProductAttributes,
-};
-
-
-export type product_type_t = "area" | "length";
-
-export const isArea = (d: dimensions_t) => ("width" in d);
-export const isLength = (d: dimensions_t) => (!("width" in d));
-export const dimensionType = (d: dimensions_t) => isArea(d) ? "area" : "length"
-
-export function matchDimensions(d1: dimensions_t, d2: dimensions_t) {
-    if (!
-        (
-            (isArea(d1) && isArea(d2)) ||
-            (isLength(d1) && isLength(d2))
-        )
-    ) {
-        throw new Error(`Dimension mismatch: ${JSON.stringify(d1)} / ${JSON.stringify(d1)}`);
-    }
-
-    return {
-        l: convert(d1.l, d1.u).to(d2.u),
-        u: d2.u,
-        ...(
-            "w" in d1 ?
-                { w: convert(d1.w, d1.u).to(d2.u), }
-                : {}
-        )
-    }
-}
-
 export function dimensionArea(d: dimensions_t) {
     return "w" in d ? d.w * d.l : 0;
 }
 
+export type ProductData = {
+    id?: Id;
+    pricePerUnit: number;
+    dimensions: dimensions_t;
+    attributes?: ProductAttributes;
+};
+
+
 export class Product {
 
     public id?: Id;

lib/rendering.tsx

@@ -2,7 +2,8 @@ import { RenderOptions, render } from "@testing-library/react-native";
 import { PropsWithChildren, ReactElement } from "react";
 import { Provider } from "react-redux";
 import { setupStore, RootState } from "@/app/store";
-import { Product, ProductData } from "@/lib/product";
+import { Product } from "@/lib/product";
+import { ProductData } from "./product";
 
 export interface ExtendedRenderOptions extends Omit<RenderOptions, 'queries'> {
     preloadedState?: Partial<RootState>;