fix(oncall-api): return all users from lowest escalation level

Instead of return all users that match the escalation level of the first user returned in the oncall list, return users that match the lowest escalation level.
Previously, if a higher escalation level user was the first item in the array, only users at that same level would be returned.

Fixes PagerDuty/backstage-plugin#77

src/apis/pagerduty.test.ts

@@ -754,6 +754,71 @@ describe("PagerDuty API", () => {
             expect(fetch).toHaveBeenCalledTimes(1);
         });
 
+        it.each(testInputs)("should return relevant users from escalation policy level 1 even if another level is returned first", async () => {
+            const escalationPolicyId = "12345";
+            const expectedResponse = [
+                {
+                    id: "userId1",
+                    name: "John Doe",
+                    email: "[email protected]",
+                    avatar_url: "https://example.pagerduty.com/avatars/123",
+                    html_url: "https://example.pagerduty.com/users/123",
+                    summary: "John Doe",
+                }
+            ];
+
+            const mockAPIResponse = {
+                "oncalls": [
+                    {
+                        "user": {
+                            "id": "userId3",
+                            "summary": "Jane Doe",
+                            "name": "Jane Doe",
+                            "email": "[email protected]",
+                            "avatar_url": "https://example.pagerduty.com/avatars/123",
+                            "html_url": "https://example.pagerduty.com/users/123",
+                        },
+                        "escalation_level": 3
+                    },
+                    {
+                        "user": {
+                            "id": expectedResponse[0].id,
+                            "summary": expectedResponse[0].summary,
+                            "name": expectedResponse[0].name,
+                            "email": expectedResponse[0].email,
+                            "avatar_url": expectedResponse[0].avatar_url,
+                            "html_url": expectedResponse[0].html_url,
+                        },
+                        "escalation_level": 1
+                    },
+                    {
+                        "user": {
+                            "id": "userId2",
+                            "summary": "James Doe",
+                            "name": "James Doe",
+                            "email": "[email protected]",
+                            "avatar_url": "https://example.pagerduty.com/avatars/123",
+                            "html_url": "https://example.pagerduty.com/users/123",
+                        },
+                        "escalation_level": 2
+                    }
+                ]
+            };
+
+            global.fetch = jest.fn(() =>
+                Promise.resolve({
+                    status: 200,
+                    json: () => Promise.resolve(mockAPIResponse)
+                })
+            ) as jest.Mock;
+
+            const result = await getOncallUsers(escalationPolicyId);
+
+            expect(result).toEqual(expectedResponse);
+            expect(result.length).toEqual(1);
+            expect(fetch).toHaveBeenCalledTimes(1);
+        });
+
         it.each(testInputs)("should return list of users ordered by name ASC from other escalation levels when level 1 is empty", async () => {
             const escalationPolicyId = "12345";
             const expectedResponse = [

src/apis/pagerduty.ts

@@ -390,7 +390,7 @@ export async function getOncallUsers(escalationPolicy: string): Promise<PagerDut
             });
 
             const oncallsFiltered = oncallsSorted.filter((oncall) => {
-                return oncall.escalation_level === result.oncalls[0].escalation_level;
+                return oncall.escalation_level === oncallsSorted[0].escalation_level;
             });
 
             usersItem = [...oncallsFiltered]