🐝 (svg-tester) move cartesian function to utils

devTools/svgTester/chart-configurations.ts

@@ -6,6 +6,7 @@ import {
     FacetStrategy,
     GrapherQueryParams,
 } from "@ourworldindata/grapher"
+import { cartesian } from "@ourworldindata/utils"
 
 export type ViewMatrix = Record<keyof GrapherQueryParams, string[]>
 
@@ -147,15 +148,6 @@ export const queryStringsByChartType = Object.fromEntries(
     })
 ) as Record<ChartTypeName, string[]>
 
-// adapted from https://stackoverflow.com/questions/12303989/cartesian-product-of-multiple-arrays-in-javascript
-function cartesian(matrix: any[][]) {
-    if (matrix.length === 0) return []
-    if (matrix.length === 1) return matrix[0].map((i) => [i])
-    return matrix.reduce((acc, curr) =>
-        acc.flatMap((i: any) => curr.map((j: any) => [i, j].flat()))
-    )
-}
-
 function toQueryStr(params: Record<string, string>): string {
     return new URLSearchParams(params).toString()
 }

packages/@ourworldindata/utils/src/Util.test.ts

@@ -28,6 +28,7 @@ import {
     greatestCommonDivisor,
     findGreatestCommonDivisorOfArray,
     traverseEnrichedBlocks,
+    cartesian,
 } from "./Util.js"
 import {
     BlockImageSize,
@@ -747,3 +748,47 @@ describe(traverseEnrichedBlocks, () => {
         ])
     })
 })
+
+describe(cartesian, () => {
+    it("returns an empty list when no arrays are provided", () => {
+        expect(cartesian([])).toEqual([])
+    })
+
+    it("returns individual items if a single array is given", () => {
+        expect(cartesian([["a", "b"]])).toEqual([["a"], ["b"]])
+    })
+
+    it("returns all possible combinations if multiple arrays are given", () => {
+        expect(cartesian([["a", "b"], ["x"]])).toEqual([
+            ["a", "x"],
+            ["b", "x"],
+        ])
+        expect(
+            cartesian([
+                ["a", "b"],
+                ["x", "y"],
+            ])
+        ).toEqual([
+            ["a", "x"],
+            ["a", "y"],
+            ["b", "x"],
+            ["b", "y"],
+        ])
+        expect(
+            cartesian([
+                ["a", "b"],
+                ["x", "y"],
+                ["+", "-"],
+            ])
+        ).toEqual([
+            ["a", "x", "+"],
+            ["a", "x", "-"],
+            ["a", "y", "+"],
+            ["a", "y", "-"],
+            ["b", "x", "+"],
+            ["b", "x", "-"],
+            ["b", "y", "+"],
+            ["b", "y", "-"],
+        ])
+    })
+})

packages/@ourworldindata/utils/src/Util.ts

@@ -1783,3 +1783,17 @@ export function checkIsDataInsight(
     const type = get(x, "content.type")
     return type === OwidGdocType.DataInsight
 }
+
+/**
+ * Returns the cartesian product of the given arrays.
+ *
+ * For example, `cartesian([["a", "b"], ["x", "y"]])` returns `[["a", "x"], ["a", "y"], ["b", "x"], ["b", "y"]]`
+ */
+export function cartesian<T>(matrix: T[][]): T[][] {
+    if (matrix.length === 0) return []
+    if (matrix.length === 1) return matrix[0].map((i) => [i])
+    return matrix.reduce<T[][]>(
+        (acc, curr) => acc.flatMap((i) => curr.map((j) => [...i, j])),
+        [[]]
+    )
+}

packages/@ourworldindata/utils/src/index.ts

@@ -116,6 +116,7 @@ export {
     copyToClipboard,
     checkIsGdocPost,
     checkIsDataInsight,
+    cartesian,
 } from "./Util.js"
 
 export {