From feb18948f530cf02720fccad3fa9165754be6666 Mon Sep 17 00:00:00 2001
From: Michael Simacek <michael.simacek@oracle.com>
Date: Tue, 29 Aug 2023 13:34:19 +0200
Subject: [PATCH] Utilize pagination when querying GraalPy GitHub releases

---
 __tests__/utils.test.ts | 25 ++++++++++++++++++++++++-
 src/install-graalpy.ts  | 26 +++++++++++++++++---------
 src/utils.ts            | 23 +++++++++++++++++++++++
 3 files changed, 64 insertions(+), 10 deletions(-)

diff --git a/__tests__/utils.test.ts b/__tests__/utils.test.ts
index 85b127a4..d294293b 100644
--- a/__tests__/utils.test.ts
+++ b/__tests__/utils.test.ts
@@ -11,7 +11,8 @@ import {
   isCacheFeatureAvailable,
   getVersionInputFromFile,
   getVersionInputFromPlainFile,
-  getVersionInputFromTomlFile
+  getVersionInputFromTomlFile,
+  getNextPageUrl
 } from '../src/utils';
 
 jest.mock('@actions/cache');
@@ -136,3 +137,25 @@ describe('Version from file test', () => {
     }
   );
 });
+
+describe('getNextPageUrl', () => {
+  it('GitHub API pagination next page is parsed correctly', () => {
+    function generateResponse(link: string) {
+      return {
+        statusCode: 200,
+        result: null,
+        headers: {
+          link: link
+        }
+      };
+    }
+    const page1Links =
+      '<https://api.github.com/repositories/129883600/releases?page=2>; rel="next", <https://api.github.com/repositories/129883600/releases?page=3>; rel="last"';
+    expect(getNextPageUrl(generateResponse(page1Links))).toStrictEqual(
+      'https://api.github.com/repositories/129883600/releases?page=2'
+    );
+    const page2Links =
+      '<https://api.github.com/repositories/129883600/releases?page=1>; rel="prev", <https://api.github.com/repositories/129883600/releases?page=1>; rel="first"';
+    expect(getNextPageUrl(generateResponse(page2Links))).toBeNull();
+  });
+});
diff --git a/src/install-graalpy.ts b/src/install-graalpy.ts
index 8f39521f..05e649e4 100644
--- a/src/install-graalpy.ts
+++ b/src/install-graalpy.ts
@@ -14,7 +14,8 @@ import {
   IGraalPyManifestRelease,
   createSymlinkInFolder,
   isNightlyKeyword,
-  getBinaryDirectory
+  getBinaryDirectory,
+  getNextPageUrl
 } from './utils';
 
 const TOKEN = core.getInput('token');
@@ -106,7 +107,6 @@ export async function installGraalPy(
 }
 
 export async function getAvailableGraalPyVersions() {
-  const url = 'https://api.github.com/repos/oracle/graalpython/releases';
   const http: httpm.HttpClient = new httpm.HttpClient('tool-cache');
 
   let headers: ifm.IHeaders = {};
@@ -114,14 +114,22 @@ export async function getAvailableGraalPyVersions() {
     headers.authorization = AUTH;
   }
 
-  const response = await http.getJson<IGraalPyManifestRelease[]>(url, headers);
-  if (!response.result) {
-    throw new Error(
-      `Unable to retrieve the list of available GraalPy versions from '${url}'`
-    );
-  }
+  let url: string | null =
+    'https://api.github.com/repos/oracle/graalpython/releases';
+  const result: IGraalPyManifestRelease[] = [];
+  do {
+    const response: ifm.ITypedResponse<IGraalPyManifestRelease[]> =
+      await http.getJson(url, headers);
+    if (!response.result) {
+      throw new Error(
+        `Unable to retrieve the list of available GraalPy versions from '${url}'`
+      );
+    }
+    result.push(...response.result);
+    url = getNextPageUrl(response);
+  } while (url);
 
-  return response.result;
+  return result;
 }
 
 async function createGraalPySymlink(
diff --git a/src/utils.ts b/src/utils.ts
index 2f4f4555..28ad8ef7 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -6,6 +6,7 @@ import * as path from 'path';
 import * as semver from 'semver';
 import * as toml from '@iarna/toml';
 import * as exec from '@actions/exec';
+import * as ifm from '@actions/http-client/interfaces';
 
 export const IS_WINDOWS = process.platform === 'win32';
 export const IS_LINUX = process.platform === 'linux';
@@ -271,3 +272,25 @@ export function getVersionInputFromFile(versionFile: string): string[] {
 export function getBinaryDirectory(installDir: string) {
   return IS_WINDOWS ? installDir : path.join(installDir, 'bin');
 }
+
+/**
+ * Extract next page URL from a HTTP response "link" header. Such headers are used in GitHub APIs.
+ */
+export function getNextPageUrl<T>(response: ifm.ITypedResponse<T>) {
+  const responseHeaders = <ifm.IHeaders>response.headers;
+  const linkHeader = responseHeaders.link;
+  if (typeof linkHeader === 'string') {
+    for (let link of linkHeader.split(/\s*,\s*/)) {
+      const match = link.match(/<([^>]+)>(.*)/);
+      if (match) {
+        const url = match[1];
+        for (let param of match[2].split(/\s*;\s*/)) {
+          if (param.match(/rel="?next"?/)) {
+            return url;
+          }
+        }
+      }
+    }
+  }
+  return null;
+}