feat: Improved recipeYield Parsing For Fractions and Decimals (#2507)

* improved recipeYield parsing for fracs/decimals

* added fix for edgecase with weird fractions

* made typescript happy

* lint

* extracted yield calculation into composable

* fixed some gross edgecases

* added tests

* made bare return clearer

---------

Co-authored-by: Hayden <64056131+hay-kot@users.noreply.github.com>

frontend/components/Domain/Recipe/RecipePage/RecipePageParts/RecipePageScale.vue

@@ -33,6 +33,8 @@ import RecipeRating from "~/components/Domain/Recipe/RecipeRating.vue";
 import { NoUndefinedField } from "~/lib/api/types/non-generated";
 import { Recipe } from "~/lib/api/types/recipe";
 import { usePageState } from "~/composables/recipe-page/shared-state";
+import { useExtractRecipeYield } from "~/composables/recipe-page/use-extract-recipe-yield";
+
 export default defineComponent({
   components: {
     RecipeScaleEditButton,
@@ -65,29 +67,11 @@ export default defineComponent({
     });
 
     const scaledYield = computed(() => {
-      const regMatchNum = /\d+/;
-      const yieldString = props.recipe.recipeYield;
-      const num = yieldString?.match(regMatchNum);
-
-      if (num && num?.length > 0) {
-        const yieldAsInt = parseInt(num[0]);
-        return yieldString?.replace(num[0], String(yieldAsInt * scaleValue.value));
-      }
-
-      return props.recipe.recipeYield;
+      return useExtractRecipeYield(props.recipe.recipeYield, scaleValue.value);
     });
 
     const basicYield = computed(() => {
-      const regMatchNum = /\d+/;
-      const yieldString = props.recipe.recipeYield;
-      const num = yieldString?.match(regMatchNum);
-
-      if (num && num?.length > 0) {
-        const yieldAsInt = parseInt(num[0]);
-        return yieldString?.replace(num[0], String(yieldAsInt));
-      }
-
-      return props.recipe.recipeYield;
+      return useExtractRecipeYield(props.recipe.recipeYield, 1);
     });
 
     return {

frontend/composables/recipe-page/use-extract-recipe-yield.test.ts

@@ -0,0 +1,111 @@
+import { describe, expect, test } from "vitest";
+import { useExtractRecipeYield } from "./use-extract-recipe-yield";
+
+describe("test use extract recipe yield", () => {
+    test("when text empty return empty", () => {
+        const result = useExtractRecipeYield(null, 1);
+        expect(result).toStrictEqual("");
+    });
+
+    test("when text matches nothing return text", () => {
+        const val = "this won't match anything";
+        const result = useExtractRecipeYield(val, 1);
+        expect(result).toStrictEqual(val);
+
+        const resultScaled = useExtractRecipeYield(val, 5);
+        expect(resultScaled).toStrictEqual(val);
+    });
+
+    test("when text matches a mixed fraction, return a scaled fraction", () => {
+        const val = "10 1/2 units";
+        const result = useExtractRecipeYield(val, 1);
+        expect(result).toStrictEqual(val);
+
+        const resultScaled = useExtractRecipeYield(val, 3);
+        expect(resultScaled).toStrictEqual("31 1/2 units");
+
+        const resultScaledPartial = useExtractRecipeYield(val, 2.5);
+        expect(resultScaledPartial).toStrictEqual("26 1/4 units");
+
+        const resultScaledInt = useExtractRecipeYield(val, 4);
+        expect(resultScaledInt).toStrictEqual("42 units");
+    });
+
+    test("when text matches a fraction, return a scaled fraction", () => {
+        const val = "1/3 plates";
+        const result = useExtractRecipeYield(val, 1);
+        expect(result).toStrictEqual(val);
+
+        const resultScaled = useExtractRecipeYield(val, 2);
+        expect(resultScaled).toStrictEqual("2/3 plates");
+
+        const resultScaledInt = useExtractRecipeYield(val, 3);
+        expect(resultScaledInt).toStrictEqual("1 plates");
+
+        const resultScaledPartial = useExtractRecipeYield(val, 2.5);
+        expect(resultScaledPartial).toStrictEqual("5/6 plates");
+
+        const resultScaledMixed = useExtractRecipeYield(val, 4);
+        expect(resultScaledMixed).toStrictEqual("1 1/3 plates");
+    });
+
+    test("when text matches a decimal, return a scaled, rounded decimal", () => {
+        const val = "1.25 parts";
+        const result = useExtractRecipeYield(val, 1);
+        expect(result).toStrictEqual(val);
+
+        const resultScaled = useExtractRecipeYield(val, 2);
+        expect(resultScaled).toStrictEqual("2.5 parts");
+
+        const resultScaledInt = useExtractRecipeYield(val, 4);
+        expect(resultScaledInt).toStrictEqual("5 parts");
+
+        const resultScaledPartial = useExtractRecipeYield(val, 2.5);
+        expect(resultScaledPartial).toStrictEqual("3.125 parts");
+
+        const roundedVal = "1.33333333333333333333 parts";
+        const resultScaledRounded = useExtractRecipeYield(roundedVal, 2);
+        expect(resultScaledRounded).toStrictEqual("2.667 parts");
+    });
+
+    test("when text matches an int, return a scaled int", () => {
+        const val = "5 bowls";
+        const result = useExtractRecipeYield(val, 1);
+        expect(result).toStrictEqual(val);
+
+        const resultScaled = useExtractRecipeYield(val, 2);
+        expect(resultScaled).toStrictEqual("10 bowls");
+
+        const resultScaledPartial = useExtractRecipeYield(val, 2.5);
+        expect(resultScaledPartial).toStrictEqual("12.5 bowls");
+
+        const resultScaledLarge = useExtractRecipeYield(val, 10);
+        expect(resultScaledLarge).toStrictEqual("50 bowls");
+    });
+
+    test("when text contains an invalid fraction, return the original string", () => {
+        const valDivZero = "3/0 servings";
+        const resultDivZero = useExtractRecipeYield(valDivZero, 3);
+        expect(resultDivZero).toStrictEqual(valDivZero);
+
+        const valDivZeroMixed = "2 4/0 servings";
+        const resultDivZeroMixed = useExtractRecipeYield(valDivZeroMixed, 6);
+        expect(resultDivZeroMixed).toStrictEqual(valDivZeroMixed);
+    });
+
+    test("when text contains a weird or small fraction, return the original string", () => {
+        const valWeird = "2323231239087/134527431962272135 servings";
+        const resultWeird = useExtractRecipeYield(valWeird, 5);
+        expect(resultWeird).toStrictEqual(valWeird);
+
+        const valSmall = "1/20230225 lovable servings";
+        const resultSmall = useExtractRecipeYield(valSmall, 12);
+        expect(resultSmall).toStrictEqual(valSmall);
+    });
+
+    test("when text contains multiple numbers, the first is parsed as the servings amount", () => {
+        const val = "100 sets of 55 bowls";
+        const result = useExtractRecipeYield(val, 3);
+        expect(result).toStrictEqual("300 sets of 55 bowls");
+    })
+});

frontend/composables/recipe-page/use-extract-recipe-yield.ts

@@ -0,0 +1,132 @@
+import { useFraction } from "~/composables/recipes";
+
+const matchMixedFraction = /(?:\d*\s\d*\d*|0)\/\d*\d*/;
+const matchFraction = /(?:\d*\d*|0)\/\d*\d*/;
+const matchDecimal = /(\d+.\d+)|(.\d+)/;
+const matchInt = /\d+/;
+
+
+
+function extractServingsFromMixedFraction(fractionString: string): number | undefined {
+    const mixedSplit = fractionString.split(/\s/);
+    const wholeNumber = parseInt(mixedSplit[0]);
+    const fraction = mixedSplit[1];
+
+    const fractionSplit = fraction.split("/");
+    const numerator = parseInt(fractionSplit[0]);
+    const denominator = parseInt(fractionSplit[1]);
+
+    if (denominator === 0) {
+        return undefined;  // if the denominator is zero, just give up
+    }
+    else {
+        return wholeNumber + (numerator / denominator);
+    }
+}
+
+function extractServingsFromFraction(fractionString: string): number | undefined {
+    const fractionSplit = fractionString.split("/");
+    const numerator = parseInt(fractionSplit[0]);
+    const denominator = parseInt(fractionSplit[1]);
+
+    if (denominator === 0) {
+        return undefined;  // if the denominator is zero, just give up
+    }
+    else {
+        return numerator / denominator;
+    }
+}
+
+
+
+function findMatch(yieldString: string): [matchString: string, servings: number, isFraction: boolean] | null {
+    if (!yieldString) {
+        return null;
+    }
+
+    const mixedFractionMatch = yieldString.match(matchMixedFraction);
+    if (mixedFractionMatch?.length) {
+        const match = mixedFractionMatch[0];
+        const servings = extractServingsFromMixedFraction(match);
+
+        // if the denominator is zero, return no match
+        if (servings === undefined) {
+            return null;
+        } else {
+            return [match, servings, true];
+        }
+    }
+
+    const fractionMatch = yieldString.match(matchFraction);
+    if (fractionMatch?.length) {
+        const match = fractionMatch[0]
+        const servings = extractServingsFromFraction(match);
+
+        // if the denominator is zero, return no match
+        if (servings === undefined) {
+            return null;
+        } else {
+            return [match, servings, true];
+        }
+    }
+
+    const decimalMatch = yieldString.match(matchDecimal);
+    if (decimalMatch?.length) {
+        const match = decimalMatch[0];
+        return [match, parseFloat(match), false];
+    }
+
+    const intMatch = yieldString.match(matchInt);
+    if (intMatch?.length) {
+        const match = intMatch[0];
+        return [match, parseInt(match), false];
+    }
+
+    return null;
+}
+
+function formatServings(servings: number, scale: number, isFraction: boolean): string {
+    const val = servings * scale;
+    if (Number.isInteger(val)) {
+        return val.toString();
+    } else if (!isFraction) {
+        return (Math.round(val * 1000) / 1000).toString();
+    }
+
+    // convert val into a fraction string
+    const { frac } = useFraction();
+
+    let valString = "";
+    const fraction = frac(val, 10, true);
+
+    if (fraction[0] !== undefined && fraction[0] > 0) {
+        valString += fraction[0];
+    }
+
+    if (fraction[1] > 0) {
+        valString += ` ${fraction[1]}/${fraction[2]}`;
+    }
+
+    return valString.trim();
+}
+
+
+export function useExtractRecipeYield(yieldString: string | null, scale: number): string {
+    if (!yieldString) {
+        return "";
+    }
+
+    const match = findMatch(yieldString);
+    if (!match) {
+        return yieldString;
+    }
+
+    const [matchString, servings, isFraction] = match;
+
+    const formattedServings = formatServings(servings, scale, isFraction);
+    if (!formattedServings) {
+        return yieldString  // this only happens with very weird or small fractions
+    } else {
+        return yieldString.replace(matchString, formatServings(servings, scale, isFraction));
+    }
+}