Code to catch the missing mandatory parameter in query (Azure#15278)

Author: sarangan12

sdk/core/core-client/src/urlHelpers.ts

@@ -133,7 +133,10 @@ function calculateQueryParameters(
         queryParameter,
         fallbackObject
       );
-      if (queryParameterValue !== undefined && queryParameterValue !== null) {
+      if (
+        (queryParameterValue !== undefined && queryParameterValue !== null) ||
+        queryParameter.mapper.required
+      ) {
         queryParameterValue = operationSpec.serializer.serialize(
           queryParameter.mapper,
           queryParameterValue,

sdk/core/core-client/test/serviceClient.spec.ts

@@ -1276,6 +1276,90 @@ describe("ServiceClient", function() {
       assert.include(error.message, "cannot be null or undefined");
     }
   });
+
+  it("should catch the mandatory parameter missing error in the query", async function() {
+    const operationSpec: OperationSpec = {
+      baseUrl: "http://localhost:3000",
+      path: "/reqopt/global/required/query",
+      httpMethod: "GET",
+      responses: {
+        200: {},
+        default: {
+          bodyMapper: {
+            type: {
+              name: "Composite",
+              className: "ErrorModel",
+              modelProperties: {
+                status: {
+                  serializedName: "status",
+                  type: {
+                    name: "Number"
+                  }
+                },
+                message: {
+                  serializedName: "message",
+                  type: {
+                    name: "String"
+                  }
+                }
+              }
+            }
+          }
+        }
+      },
+      headerParameters: [
+        {
+          parameterPath: "accept",
+          mapper: {
+            defaultValue: "application/json",
+            isConstant: true,
+            serializedName: "Accept",
+            type: {
+              name: "String"
+            }
+          }
+        }
+      ],
+      queryParameters: [
+        {
+          parameterPath: "requiredGlobalQuery",
+          mapper: {
+            serializedName: "required-global-query",
+            required: true,
+            type: {
+              name: "String"
+            }
+          }
+        }
+      ],
+      serializer: createSerializer()
+    };
+
+    let request: OperationRequest;
+    const pipeline = createEmptyPipeline();
+    pipeline.addPolicy(serializationPolicy(), { phase: "Serialize" });
+    const client = new ServiceClient({
+      httpClient: {
+        sendRequest: (req) => {
+          request = req;
+          return Promise.resolve({ request, status: 200, headers: createHttpHeaders() });
+        }
+      },
+      pipeline
+    });
+
+    try {
+      await client.sendOperationRequest(
+        {
+          options: undefined
+        },
+        operationSpec
+      );
+      assert.fail("Expected client to throw");
+    } catch (error) {
+      assert.include(error.message, "cannot be null or undefined");
+    }
+  });
 });
 
 async function testSendOperationRequest(