feat(medusa, medusa-js, medusa-react): Implement Sales Channel list (#1815)

**What**
Support sales channel list in medusa, medusa-js and medusa-react

**How**

By implementing a new endpoint and the associated service method as well as the repository methods.

Medusa-js new list method in the resource

Medusa-react new hook in the queries

**Tests**

Endpoint test
Service test
Integration test
Hook tests

Fixes CORE-280

packages/medusa/src/utils/__tests__/remove-undefined-properties.spec.ts

@@ -0,0 +1,47 @@
+import { removeUndefinedProperties } from "../remove-undefined-properties";
+
+describe("removeUndefinedProperties", ()  => {
+  it("should remove all undefined properties from an input object", () => {
+    const inputObj = {
+      test: undefined,
+      test1: "test1",
+      test2: null,
+      test3: {
+        test3_1: undefined,
+        test3_2: "test3_2",
+        test3_3: null,
+      },
+      test4: [
+        undefined,
+        null,
+        "null",
+        [1, 2, undefined],
+        {
+          test4_1: undefined,
+          test4_2: "test4_2",
+          test4_3: null,
+        }
+      ]
+    }
+
+    const cleanObject = removeUndefinedProperties(inputObj)
+
+    expect(cleanObject).toEqual({
+      test1: "test1",
+      test2: null,
+      test3: {
+        test3_2: "test3_2",
+        test3_3: null,
+      },
+      test4: [
+        null,
+        null,
+        [1, 2],
+        {
+          test4_2: "test4_2",
+          test4_3: null
+        }
+      ]
+    })
+  })
+})

packages/medusa/src/utils/index.ts

@@ -1,4 +1,5 @@
-export * from './build-query'
-export * from './set-metadata'
-export * from './validate-id'
-export * from './generate-entity-id'
+export * from "./build-query"
+export * from "./set-metadata"
+export * from "./validate-id"
+export * from "./generate-entity-id"
+export * from "./remove-undefined-properties"

packages/medusa/src/utils/remove-undefined-properties.ts

@@ -0,0 +1,41 @@
+export function removeUndefinedProperties<T extends object>(inputObj: T): T {
+  const removeProperties = (obj: T) => {
+    const res = {} as T
+
+    Object.keys(obj).reduce((acc: T, key: string) => {
+      if (typeof obj[key] === "undefined") {
+        return acc
+      }
+      acc[key] = removeUndefinedDeeply(obj[key])
+      return acc
+    }, res)
+
+    return res
+  }
+
+  return removeProperties(inputObj)
+}
+
+function removeUndefinedDeeply(input: unknown): any {
+  if (typeof input !== "undefined") {
+    if (input === null || input === "null") {
+      return null
+    } else if (Array.isArray(input)) {
+      return input.map((item) => {
+        return removeUndefinedDeeply(item)
+      }).filter(v => typeof v !== "undefined")
+    } else if (Object.prototype.toString.call(input) === '[object Date]') {
+      return input
+    } else if (typeof input === "object") {
+       return Object.keys(input).reduce((acc: Record<string, unknown>, key: string) => {
+         if (typeof input[key] === "undefined") {
+           return acc
+         }
+         acc[key] = removeUndefinedDeeply(input[key])
+         return acc
+       }, {})
+    } else {
+      return input
+    }
+  }
+}