Only fetch checksums for unknown wrapper versions (#292)

The checksum values for most wrapper versions are hard-coded into the
action. These known checksum values are first used for validation: only
if none of the known values work do we download checksums.

Previously, we blindly downloaded all of the checksum values in this
case: we now only download the checksums for versions that are not in
our "known" set.

Fixes #171

sources/src/wrapper-validation/checksums.ts

@@ -4,21 +4,27 @@ import fileWrapperChecksums from './wrapper-checksums.json'
 
 const httpc = new httpm.HttpClient('gradle/wrapper-validation-action', undefined, {allowRetries: true, maxRetries: 3})
 
-function getKnownValidChecksums(): Map<string, Set<string>> {
+export class WrapperChecksums {
-    const versionsMap = new Map<string, Set<string>>()
+    checksums = new Map<string, Set<string>>()
+    versions = new Set<string>()
+
+    add(version: string, checksum: string): void {
+        if (this.checksums.has(checksum)) {
+            this.checksums.get(checksum)!.add(version)
+        } else {
+            this.checksums.set(checksum, new Set([version]))
+        }
+
+        this.versions.add(version)
+    }
+}
+
+function loadKnownChecksums(): WrapperChecksums {
+    const checksums = new WrapperChecksums()
     for (const entry of fileWrapperChecksums) {
-        const checksum = entry.checksum
+        checksums.add(entry.version, entry.checksum)
-
-        let versionNames = versionsMap.get(checksum)
-        if (versionNames === undefined) {
-            versionNames = new Set()
-            versionsMap.set(checksum, versionNames)
     }
-
+    return checksums
-        versionNames.add(entry.version)
-    }
-
-    return versionsMap
 }
 
 /**
@@ -26,9 +32,12 @@ function getKnownValidChecksums(): Map<string, Set<string>> {
  *
  * Maps from the checksum to the names of the Gradle versions whose wrapper has this checksum.
  */
-export const KNOWN_VALID_CHECKSUMS = getKnownValidChecksums()
+export const KNOWN_CHECKSUMS = loadKnownChecksums()
 
-export async function fetchValidChecksums(allowSnapshots: boolean): Promise<Set<string>> {
+export async function fetchUnknownChecksums(
+    allowSnapshots: boolean,
+    knownChecksums: WrapperChecksums
+): Promise<Set<string>> {
     const all = await httpGetJsonArray('https://services.gradle.org/versions/all')
     const withChecksum = all.filter(
         entry => typeof entry === 'object' && entry != null && entry.hasOwnProperty('wrapperChecksumUrl')
@@ -37,7 +46,11 @@ export async function fetchValidChecksums(allowSnapshots: boolean): Promise<Set<
         // eslint-disable-next-line @typescript-eslint/no-explicit-any
         (entry: any) => allowSnapshots || !entry.snapshot
     )
-    const checksumUrls = allowed.map(
+    const notKnown = allowed.filter(
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        (entry: any) => !knownChecksums.versions.has(entry.version)
+    )
+    const checksumUrls = notKnown.map(
         // eslint-disable-next-line @typescript-eslint/no-explicit-any
         (entry: any) => entry.wrapperChecksumUrl as string
     )

sources/src/wrapper-validation/validate.ts

@@ -8,7 +8,7 @@ export async function findInvalidWrapperJars(
     minWrapperCount: number,
     allowSnapshots: boolean,
     allowedChecksums: string[],
-    knownValidChecksums: Map<string, Set<string>> = checksums.KNOWN_VALID_CHECKSUMS
+    knownValidChecksums: checksums.WrapperChecksums = checksums.KNOWN_CHECKSUMS
 ): Promise<ValidationResult> {
     const wrapperJars = await find.findWrapperJars(gitRepoRoot)
     const result = new ValidationResult([], [])
@@ -21,7 +21,7 @@ export async function findInvalidWrapperJars(
         const notYetValidatedWrappers = []
         for (const wrapperJar of wrapperJars) {
             const sha = await hash.sha256File(resolve(gitRepoRoot, wrapperJar))
-            if (allowedChecksums.includes(sha) || knownValidChecksums.has(sha)) {
+            if (allowedChecksums.includes(sha) || knownValidChecksums.checksums.has(sha)) {
                 result.valid.push(new WrapperJar(wrapperJar, sha))
             } else {
                 notYetValidatedWrappers.push(new WrapperJar(wrapperJar, sha))
@@ -31,7 +31,7 @@ export async function findInvalidWrapperJars(
         // Otherwise fall back to fetching checksums from Gradle API and compare against them
         if (notYetValidatedWrappers.length > 0) {
             result.fetchedChecksums = true
-            const fetchedValidChecksums = await checksums.fetchValidChecksums(allowSnapshots)
+            const fetchedValidChecksums = await checksums.fetchUnknownChecksums(allowSnapshots, knownValidChecksums)
 
             for (const wrapperJar of notYetValidatedWrappers) {
                 if (!fetchedValidChecksums.has(wrapperJar.checksum)) {

sources/test/jest/wrapper-validation/checksums.test.ts

@@ -6,22 +6,22 @@ jest.setTimeout(30000)
 
 test('has loaded hardcoded wrapper jars checksums', async () => {
   // Sanity check that generated checksums file is not empty and was properly imported
-  expect(checksums.KNOWN_VALID_CHECKSUMS.size).toBeGreaterThan(10)
+  expect(checksums.KNOWN_CHECKSUMS.checksums.size).toBeGreaterThan(10)
   // Verify that checksums of arbitrary versions are contained
   expect(
-    checksums.KNOWN_VALID_CHECKSUMS.get(
+    checksums.KNOWN_CHECKSUMS.checksums.get(
       '660ab018b8e319e9ae779fdb1b7ac47d0321bde953bf0eb4545f14952cfdcaa3'
     )
   ).toEqual(new Set(['4.10.3']))
   expect(
-    checksums.KNOWN_VALID_CHECKSUMS.get(
+    checksums.KNOWN_CHECKSUMS.checksums.get(
       '28b330c20a9a73881dfe9702df78d4d78bf72368e8906c70080ab6932462fe9e'
     )
   ).toEqual(new Set(['6.0-rc-1', '6.0-rc-2', '6.0-rc-3', '6.0', '6.0.1']))
 })
 
 test('fetches wrapper jars checksums', async () => {
-  const validChecksums = await checksums.fetchValidChecksums(false)
+  const validChecksums = await checksums.fetchUnknownChecksums(false, new checksums.WrapperChecksums)
   expect(validChecksums.size).toBeGreaterThan(10)
   // Verify that checksum of arbitrary version is contained
   expect(
@@ -47,7 +47,7 @@ describe('retry', () => {
           code: 'ECONNREFUSED'
         })
 
-      const validChecksums = await checksums.fetchValidChecksums(false)
+      const validChecksums = await checksums.fetchUnknownChecksums(false, new checksums.WrapperChecksums)
       expect(validChecksums.size).toBeGreaterThan(10)
       nock.isDone()
     })

sources/test/jest/wrapper-validation/validate.test.ts

@@ -1,6 +1,7 @@
 import * as path from 'path'
 import * as validate from '../../../src/wrapper-validation/validate'
 import {expect, test, jest} from '@jest/globals'
+import { WrapperChecksums } from '../../../src/wrapper-validation/checksums'
 
 jest.setTimeout(30000)
 
@@ -24,7 +25,7 @@ test('succeeds if all found wrapper jars are valid', async () => {
 })
 
 test('succeeds if all found wrapper jars are valid (and checksums are fetched from Gradle API)', async () => {
-  const knownValidChecksums = new Map<string, Set<string>>()
+  const knownValidChecksums = new WrapperChecksums()
   const result = await validate.findInvalidWrapperJars(
     baseDir,
     1,
@@ -32,6 +33,7 @@ test('succeeds if all found wrapper jars are valid (and checksums are fetched fr
     ['e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855'],
     knownValidChecksums
   )
+  console.log(`fetchedChecksums = ${result.fetchedChecksums}`)
 
   expect(result.isValid()).toBe(true)
   // Should have fetched checksums because no known checksums were provided