test: add tests for FuzzySearch

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

@@ -0,0 +1,105 @@
+import { FuzzySearch } from "./FuzzySearch.js"
+
+describe(FuzzySearch, () => {
+    const countries = [
+        { name: "United States", population: 329.5 },
+        { name: "United Kingdom", population: 67.2 },
+        { name: "Germany", population: 83.2 },
+        { name: "France", population: 67.4 },
+        { name: "Spain", population: 47.4 },
+        { name: "Italy", population: 60.3 },
+    ]
+
+    describe("withKey", () => {
+        it("creates a fuzzy search instance with a key function", () => {
+            const search = FuzzySearch.withKey(
+                countries,
+                (country) => country.name
+            )
+            expect(search).toBeInstanceOf(FuzzySearch)
+        })
+
+        it("finds results based on fuzzy matching", () => {
+            const search = FuzzySearch.withKey(
+                countries,
+                (country) => country.name
+            )
+            const results = search.search("united")
+            expect(results).toHaveLength(2)
+            expect(results.map((c) => c.name).sort()).toEqual([
+                "United Kingdom",
+                "United States",
+            ])
+        })
+
+        it("returns empty array for no matches", () => {
+            const search = FuzzySearch.withKey(
+                countries,
+                (country) => country.name
+            )
+            const results = search.search("australia")
+            expect(results).toHaveLength(0)
+        })
+
+        it("handles empty search input", () => {
+            const search = FuzzySearch.withKey(
+                countries,
+                (country) => country.name
+            )
+            const results = search.search("")
+            expect(results).toHaveLength(0)
+        })
+
+        it("can handle a single key pointing to multiple values", () => {
+            const data = [
+                { name: "GDP", chart: "gdp-world-bank" },
+                { name: "GDP", chart: "gdp-maddison" },
+            ]
+            const search = FuzzySearch.withKey(data, (d) => d.name)
+            const results = search.search("GDP")
+            expect(results).toHaveLength(2)
+            expect(results.map((d) => d.chart).sort()).toEqual([
+                "gdp-maddison",
+                "gdp-world-bank",
+            ])
+        })
+    })
+
+    describe("searchResults", () => {
+        it("returns raw fuzzysort results", () => {
+            const search = FuzzySearch.withKey(
+                countries,
+                (country) => country.name
+            )
+            const results = search.searchResults("united")
+
+            expect(results).toBeInstanceOf(Array)
+            expect(results.length).toBe(2)
+            expect(results[0]).toHaveProperty("target")
+            expect(results[0]).toHaveProperty("score")
+        })
+    })
+
+    describe("single", () => {
+        it("performs fuzzy match against a single target", () => {
+            const search = FuzzySearch.withKey(
+                countries,
+                (country) => country.name
+            )
+            const result = search.single("germny", "Germany")
+
+            expect(result).not.toBeNull()
+            expect(result?.target).toBe("Germany")
+        })
+
+        it("returns null for no match", () => {
+            const search = FuzzySearch.withKey(
+                countries,
+                (country) => country.name
+            )
+            const result = search.single("xyz", "Germany")
+
+            expect(result).toBeNull()
+        })
+    })
+})