chore: example for setters argument for @rest directive (#68)

* chore: example for  setters argument for @rest directive

Signed-off-by: asararatnakar <asara.ratnakar@gmail.com>

* prettify

Signed-off-by: asararatnakar <asara.ratnakar@gmail.com>

* removed the rest call and simulated JSON response as suggested

Signed-off-by: asararatnakar <asara.ratnakar@gmail.com>

* update comments

Signed-off-by: asararatnakar <asara.ratnakar@gmail.com>

* minor edits:

Signed-off-by: asararatnakar <asara.ratnakar@gmail.com>

* address comments

Signed-off-by: asararatnakar <asara.ratnakar@gmail.com>

* change names to look better

Signed-off-by: asararatnakar <asara.ratnakar@gmail.com>

---------

Signed-off-by: asararatnakar <asara.ratnakar@gmail.com>

Author: asararatnakar

transforms/README.md

@@ -10,3 +10,4 @@ For more on what `transforms` is and how it operates within the custom `@rest` d
 - [combineintostring](combineintostring) shows how a new field in the return type can be created by concatenating some other fields (like address parts into one address)
 - [jsonarrayToJsonobject](jsonarrayToJsonobject) shows how an array of data (say coords) can be converted into an object, `{"lat":, "lon",..}` so that it can be fed into some other system that requires data to be expressed that way
 - [jsonobjectToJsonarray](jsonobjectToJsonarray) shows how an object (typically where each key is an id of a record) can be converted into an array (e.g., `{"1":{"name": "john"}, "2": "jane"}` can be converted to `[{"id":"1", "name": "john"}, {"id":"2", name: "jane"}]`), so that it can then behave well for GraphQL processing.
+- [setters](setters) shows how to map a JSON response values to the fields of the GraphQL type.

transforms/jsonobjectToJsonarray/api.graphql

@@ -58,20 +58,10 @@ type Query {
       # StepZen takes care of calling jq for each element.
       transforms: [
         { pathpattern: ["<>*"], editor: "objectToArray" }
-        # you could comment this out if you want to try setters instead
         {
           pathpattern: ["[]*"]
           editor: "jq:.[]|{id:.name,fullName:.value.fullName,age:.value.age}"
         }
       ]
-
-      # for the second transformation, you can use setters. Uncomment the next line and comment the second pathpattern line above to see how it operates.
-      # In order to make this to work, change the return type from JSON to [Customer].
-
-      # setters: [
-      #   { field: "id", path: "name" }
-      #   { field: "fullName", path: "value.fullName" }
-      #   { field: "age", path: "value.age" }
-      # ]
     )
 }

transforms/setters/api.graphql

@@ -0,0 +1,41 @@
+# This example illustrates how to map a JSON response to the fields of a GraphQL object.
+
+type Customer {
+  id: ID
+  name: String
+  address: Address
+}
+
+type Address {
+  city: String
+  country: String
+  state: String
+  street: String
+  postalCode: String
+}
+
+type Query {
+  # ecmascript generates customer data to simulate a REST api with a JSON response.
+  # To verify with a real data source (API or a database) it is required to change the `endpoint` argument on the `@rest` directive.
+  # https://stepzen.com/docs/connecting-backends/how-to-connect-a-rest-service
+  customer(id: ID!): Customer
+    @rest(
+      endpoint: "stepzen:empty"
+      ecmascript: """
+      function transformREST() {
+          var id = get('id')
+          if (id==1)
+            return ({"location":{"address":{"city":"Raleigh","country":"USA","postalCode":"54321","state":"NC","street":"101 Main St"}},"customerId":"12345","customerName":"John Doe"})
+          else
+            return ({"location":{"address":{"city":"Hyderabad","country":"India","postalCode":"654231","state":"TS","street":"J.N.T.U Colony"}},"customerId":"21345","customerName":"Siddarth A"})
+      }
+      """
+
+      # mapping from JSON response values to the fields of the GraphQL result.
+      setters: [
+        { field: "id", path: "customerId" } # JSON response field 'customerId' is mapped to GraphQL 'id'
+        { field: "name", path: "customerName" } # JSON response field 'customerName' is mapped to GraphQL 'name'
+        { field: "address", path: "location.address" } # JSON response nested field 'location.address' mapped to GraphQL 'address'
+      ]
+    )
+}

transforms/setters/index.graphql

@@ -0,0 +1,3 @@
+schema @sdl(files: ["api.graphql"]) {
+  query: Query
+}

transforms/setters/requests.graphql

@@ -0,0 +1,12 @@
+# maps some of JSON response values to the fields of the GraphQL result.
+query CustomerByID($id: ID!) {
+  customer(id: $id) {
+    address {
+      city
+      state
+      country
+    }
+    id
+    name
+  }
+}

transforms/setters/stepzen.config.json

@@ -0,0 +1,3 @@
+{
+  "endpoint": "api/miscellaneous"
+}

transforms/setters/tests/Test.js

@@ -0,0 +1,52 @@
+const fs = require("fs");
+const path = require("node:path");
+const {
+  deployAndRun,
+  stepzen,
+  getTestDescription,
+} = require("../../../tests/gqltest.js");
+
+testDescription = getTestDescription("snippets", __dirname);
+
+const requestsFile = path.join(path.dirname(__dirname), "requests.graphql");
+const requests = fs.readFileSync(requestsFile, "utf8").toString();
+
+describe(testDescription, function () {
+  const tests = [
+    {
+      label: "customer-by-id-1",
+      query: requests,
+      operationName: "CustomerByID",
+      variables: { id: 1 },
+      expected: {
+        customer: {
+          address: {
+            city: "Raleigh",
+            country: "USA",
+            state: "NC",
+          },
+          id: "12345",
+          name: "John Doe",
+        },
+      },
+    },
+    {
+      label: "customer-by-id-100",
+      query: requests,
+      operationName: "CustomerByID",
+      variables: { id: 100 },
+      expected: {
+        customer: {
+          address: {
+            city: "Hyderabad",
+            country: "India",
+            state: "TS",
+          },
+          id: "21345",
+          name: "Siddarth A",
+        },
+      },
+    },
+  ];
+  return deployAndRun(__dirname, tests, stepzen.admin);
+});