Implement unique value filtering in parseArray function and add corresponding tests. Updated function signature to accept an options object for separator and uniqueValues. Enhanced filtering logic to support duplicate removal based on the uniqueValues option.

Author: ogroppo

src/helpers/parseArray.test.ts

@@ -17,4 +17,28 @@ describe("parseArray", () => {
     expect(parseArray("a|b|c", { separator: "|" })).toEqual(["a", "b", "c"]);
     expect(parseArray("x; y ;z", { separator: ";" })).toEqual(["x", "y", "z"]);
   });
+
+  test("uniqueValues removes duplicates", () => {
+    expect(
+      parseArray("a,b;a;c;b,a", { separator: ";", uniqueValues: true })
+    ).toEqual(["a,b", "a", "c", "b,a"]);
+    expect(parseArray("a,b,a,c,b", { uniqueValues: true })).toEqual([
+      "a",
+      "b",
+      "c",
+    ]);
+  });
+
+  test("uniqueValues keeps duplicates when false", () => {
+    expect(parseArray("a,b,a,c,b")).toEqual(["a", "b", "a", "c", "b"]);
+    expect(parseArray("a,b,a", { uniqueValues: false })).toEqual([
+      "a",
+      "b",
+      "a",
+    ]);
+  });
+
+  test("uniqueValues with numeric-like values", () => {
+    expect(parseArray("1,2,1,3", { uniqueValues: true })).toEqual([1, 2, 3]);
+  });
 });

src/helpers/parseArray.ts

@@ -1,3 +1,4 @@
+import { isEmptyString } from "../validators";
 import { ParsedPrimitive, parsePrimitive } from "./parsePrimitive";
 
 /**
@@ -8,12 +9,22 @@ import { ParsedPrimitive, parsePrimitive } from "./parsePrimitive";
  */
 export const parseArray = (
   str: string,
-  options?: { separator?: string }
+  {
+    separator = ",",
+    uniqueValues = false,
+  }: { separator?: string; uniqueValues?: boolean } = {}
 ): ParsedPrimitive[] => {
-  const { separator = "," } = options ?? {};
-
   return str
     .split(separator)
     .map((v) => parsePrimitive(v))
-    .filter(Boolean);
+    .filter((v, index, self) => {
+      // Keep 0, null, undefined etc. but not empty strings
+      if (isEmptyString(v as string)) {
+        return false;
+      }
+      if (uniqueValues) {
+        return self.indexOf(v) === index; // keep it simple, don't use Set
+      }
+      return true;
+    });
 };