refactor: implement updated equality heuristics for hopprestrequest struct

packages/hoppscotch-data/src/utils/eq.ts

@@ -0,0 +1,50 @@
+import * as Eq from "fp-ts/Eq"
+import * as S from "fp-ts/string"
+import isEqual from "lodash/isEqual"
+
+/*
+ * Eq-s are fp-ts an interface (type class) that defines how the equality
+ * of 2 values of a certain type are matched as equal
+ */
+
+
+/**
+ * Create an Eq from a non-undefinable value and makes it accept undefined
+ * @param eq The non nullable Eq to add to
+ * @returns The updated Eq which accepts undefined
+ */
+export const undefinedEq = <T>(eq: Eq.Eq<T>): Eq.Eq<T | undefined> => ({
+  equals(x: T | undefined, y: T | undefined) {
+    if (x !== undefined && y !== undefined) {
+      return eq.equals(x, y)
+    }
+
+    return x === undefined && y === undefined
+  }
+})
+
+/**
+ * An Eq which compares by transforming based on a mapping function and then applying the Eq to it
+ * @param map The mapping function to map values to
+ * @param eq The Eq which takes the value which the map returns
+ * @returns An Eq which takes the input of the mapping function
+ */
+export const mapThenEq = <A, B>(map: (x: A) => B, eq: Eq.Eq<B>): Eq.Eq<A> => ({
+  equals(x: A, y: A) {
+    return eq.equals(map(x), map(y))
+  }
+})
+
+/**
+ * An Eq which checks equality of 2 string in a case insensitive way
+ */
+export const stringCaseInsensitiveEq: Eq.Eq<string> = mapThenEq(S.toLowerCase, S.Eq)
+
+/**
+ * An Eq that does equality check with Lodash's isEqual function
+ */
+export const lodashIsEqualEq: Eq.Eq<any> = {
+  equals(x: any, y: any) {
+    return isEqual(x, y)
+  }
+}