cli: fixes for success cache hashing for workspace path and .eslintignore

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

.changeset/afraid-bananas-behave.md

@@ -0,0 +1,5 @@
+---
+'@backstage/cli': patch
+---
+
+Fixed an issue where the `--successCache` option for the `repo test` and `repo lint` commands would be include the workspace path in generated cache keys. This previously broke caching in environments where the workspace path varies across builds.

.changeset/short-geckos-sniff.md

@@ -0,0 +1,5 @@
+---
+'@backstage/cli': patch
+---
+
+Fixed an issue with the `repo lint` command where the cache key for the `--successCache` option would not properly ignore files that should be ignored according to `.eslintignore`s.

packages/cli/src/commands/repo/lint.ts

@@ -125,8 +125,7 @@ export async function command(opts: OptionValues, cmd: Command): Promise<void> {
       const globby = require('globby') as typeof import('globby');
       const { readFile } =
         require('fs/promises') as typeof import('fs/promises');
-      const { relative: workerRelativePath } =
-        require('path') as typeof import('path');
+      const workerPath = require('path') as typeof import('path');
 
       return async ({
         fullDir,
@@ -163,15 +162,20 @@ export async function command(opts: OptionValues, cmd: Command): Promise<void> {
           hash.update('\0');
 
           for (const path of result.sort()) {
-            if (await eslint.isPathIgnored(path)) {
+            const absPath = workerPath.resolve(rootDir, path);
+            const pathInPackage = workerPath.relative(fullDir, absPath);
+
+            if (await eslint.isPathIgnored(pathInPackage)) {
               continue;
             }
-            hash.update(workerRelativePath(fullDir, path));
+            hash.update(pathInPackage);
             hash.update('\0');
-            hash.update(await readFile(path));
+            hash.update(await readFile(absPath));
             hash.update('\0');
             hash.update(
-              JSON.stringify(await eslint.calculateConfigForFile(path)),
+              JSON.stringify(
+                await eslint.calculateConfigForFile(pathInPackage),
+              ).replaceAll(rootDir, ''),
             );
             hash.update('\0');
           }

packages/cli/src/commands/repo/test.ts

@@ -300,7 +300,9 @@ export async function command(opts: OptionValues, cmd: Command): Promise<void> {
         baseHash.update('\0');
         baseHash.update(process.version); // Node.js version
         baseHash.update('\0');
-        baseHash.update(JSON.stringify(globalRootConfig)); // Variable global jest config
+        baseHash.update(
+          SuccessCache.trimPaths(JSON.stringify(globalRootConfig)),
+        ); // Variable global jest config
         const baseSha = baseHash.digest('hex');
 
         return projectConfigs.filter(project => {
@@ -326,7 +328,7 @@ export async function command(opts: OptionValues, cmd: Command): Promise<void> {
 
           // The project ID is a hash of the transform configuration, which helps
           // us bust the cache when any changes are made to the transform implementation.
-          hash.update(JSON.stringify(project));
+          hash.update(SuccessCache.trimPaths(JSON.stringify(project)));
           hash.update(lockfile.getDependencyTreeHash(packageName));
 
           const sha = hash.digest('hex');

packages/cli/src/lib/cache/SuccessCache.ts

@@ -16,6 +16,7 @@
 
 import fs from 'fs-extra';
 import { resolve as resolvePath } from 'node:path';
+import { paths } from '../paths';
 
 const DEFAULT_CACHE_BASE_PATH = 'node_modules/.cache/backstage-cli';
 
@@ -24,6 +25,15 @@ const CACHE_MAX_AGE_MS = 7 * 24 * 3600_000;
 export class SuccessCache {
   readonly #path: string;
 
+  /**
+   * Trim any occurrences of the workspace root path from the input string. This
+   * is useful to ensure stable hashes that don't vary based on the workspace
+   * location.
+   */
+  static trimPaths(input: string) {
+    return input.replaceAll(paths.targetRoot, '');
+  }
+
   constructor(name: string, basePath?: string) {
     this.#path = resolvePath(basePath ?? DEFAULT_CACHE_BASE_PATH, name);
   }