Switch to using other link header parser

Signed-off-by: Robert Bunning <rbunning@webstaurantstore.com>

plugins/newrelic/package.json

@@ -39,6 +39,8 @@
     "@material-ui/core": "^4.12.2",
     "@material-ui/icons": "^4.9.1",
     "@material-ui/lab": "4.0.0-alpha.61",
+    "@types/parse-link-header": "^2.0.1",
+    "parse-link-header": "^2.0.0",
     "react-use": "^17.2.4"
   },
   "peerDependencies": {

plugins/newrelic/src/api/index.test.ts

@@ -126,7 +126,7 @@ describe('NewRelicClient', () => {
           headers: new Map<string, string | null>([
             [
               'link',
-              '<https://next.page/page2?page=2>; rel="next", <https://badsite.dontgohere>; rel="next"',
+              '<https://next.page/page2?page=2>; rel="next", <https://badsite.dontgohere>; rel="first"',
             ],
             ['otherheader', 'otherValue'],
           ]),

plugins/newrelic/src/api/index.ts

@@ -20,6 +20,8 @@ import {
   FetchApi,
 } from '@backstage/core-plugin-api';
 
+import parseLinkHeader from 'parse-link-header';
+
 export type NewRelicApplication = {
   id: number;
   application_summary: NewRelicApplicationSummary;
@@ -76,14 +78,8 @@ export interface NewRelicApi {
   getApplications(): Promise<NewRelicApplications>;
 }
 
-interface PaginationInformation {
-  nextPageLink: string;
-  relation: string;
-}
-
 interface NewRelicPageReadResult {
-  hasMoreApplications: boolean;
-  pagination: PaginationInformation | undefined;
+  nextPageUrl: string | undefined;
   applicationsFromReadPage: NewRelicApplication[];
 }
 
@@ -106,20 +102,17 @@ export class NewRelicClient implements NewRelicApi {
       this.baseUrl = `${proxyUrl}${this.proxyPathBase}/apm/api/applications.json`;
     }
 
-    let targetUrl = this.baseUrl;
-    let hasNextPage = true;
-
     try {
       let applications: NewRelicApplication[] = [];
+      let targetUrl = this.baseUrl;
 
       do {
-        const { hasMoreApplications, pagination, applicationsFromReadPage } =
+        const { nextPageUrl, applicationsFromReadPage } =
           await this.fetchNewRelic(targetUrl);
 
-        hasNextPage = hasMoreApplications;
-        targetUrl = hasNextPage ? pagination!.nextPageLink : '';
+        targetUrl = nextPageUrl ?? '';
         applications = applications.concat(applicationsFromReadPage);
-      } while (hasNextPage);
+      } while (!!targetUrl);
 
       return { applications };
     } catch (e) {
@@ -143,37 +136,12 @@ export class NewRelicClient implements NewRelicApi {
 
     const readResponse = responseJson as NewRelicApplications;
     const linkHeader = response.headers.get('link');
-    const pagination = this.parseLinkHeader(linkHeader);
+    const parseResult = parseLinkHeader(linkHeader);
+    const nextPageNumber = parseResult?.next?.page;
 
     return {
-      hasMoreApplications: !!(pagination && pagination.relation === 'next'),
-      pagination,
+      nextPageUrl: nextPageNumber && `${this.baseUrl}?page=${nextPageNumber}`,
       applicationsFromReadPage: readResponse.applications,
     };
   }
-
-  private parseLinkHeader(
-    linkHeader: string | null,
-  ): PaginationInformation | undefined {
-    if (!linkHeader) {
-      return undefined;
-    }
-
-    const nextRelevantLink = linkHeader.replaceAll(' ', '').split(',')[0];
-    const linkParts = nextRelevantLink.match(/^<.+(\?page=.+)>;rel="(.+)"$/);
-    const nextPageNumber = linkParts?.[1];
-    const relation = linkParts?.[2];
-
-    const nextPageLink = `${this.baseUrl}${nextPageNumber}`;
-    const isValidLink = !!(linkParts && nextPageNumber && relation);
-
-    if (!nextRelevantLink || !isValidLink) {
-      return undefined;
-    }
-
-    return {
-      nextPageLink,
-      relation,
-    };
-  }
 }

yarn.lock

@@ -7605,9 +7605,11 @@ __metadata:
     "@testing-library/react": ^12.1.3
     "@testing-library/user-event": ^14.0.0
     "@types/node": ^16.11.26
+    "@types/parse-link-header": ^2.0.1
     "@types/react": ^16.13.1 || ^17.0.0
     cross-fetch: ^3.1.5
     msw: ^1.0.0
+    parse-link-header: ^2.0.0
     react-use: ^17.2.4
   peerDependencies:
     react: ^16.13.1 || ^17.0.0
@@ -17606,6 +17608,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/parse-link-header@npm:^2.0.1":
+  version: 2.0.1
+  resolution: "@types/parse-link-header@npm:2.0.1"
+  checksum: f76678612511365aefc23704f00f3262fcb1d6bd9c4dd83f783a38e50e3ccf26615f9a62c757952cab5af6f2bd8b3b1763ce391376458afce5fe47c6fe2b80e1
+  languageName: node
+  linkType: hard
+
 "@types/passport-auth0@npm:^1.0.5":
   version: 1.0.5
   resolution: "@types/passport-auth0@npm:1.0.5"
@@ -34337,6 +34346,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"parse-link-header@npm:^2.0.0":
+  version: 2.0.0
+  resolution: "parse-link-header@npm:2.0.0"
+  dependencies:
+    xtend: ~4.0.1
+  checksum: 0e96c6af9910e8f92084b49b8dc6a10dd58db470847d1499f562576180c1ac5e49d18007697f0d538e5f3efdc8ce1d8777641f3ae225302b74af0dd0578b628e
+  languageName: node
+  linkType: hard
+
 "parse-path@npm:^7.0.0":
   version: 7.0.0
   resolution: "parse-path@npm:7.0.0"
@@ -42745,7 +42763,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"xtend@npm:^4.0.0":
+"xtend@npm:^4.0.0, xtend@npm:~4.0.1":
   version: 4.0.2
   resolution: "xtend@npm:4.0.2"
   checksum: ac5dfa738b21f6e7f0dd6e65e1b3155036d68104e67e5d5d1bde74892e327d7e5636a076f625599dc394330a731861e87343ff184b0047fef1360a7ec0a5a36a