fix(core): avoid tsconfig path false positives for sibling project roots

[cw-alexcroteau]

Current Behavior

Root tsconfig path changes can mark sibling project roots as touched when they only share a string prefix.

Expected Behavior

Only the project whose root contains the changed path, or exactly matches it, should be marked as touched.

Related Issue(s)

Fixes #35795

Summary

• avoid false positives in getTouchedProjectsFromTsConfig for sibling roots with shared prefixes
• add a regression test covering libs/typescript/cdk vs libs/typescript/cdk-utils
• include external repro evidence:
  • https://github.com/cw-alexcroteau/nx-tsconfig-path-prefix-false-positive-repro-20260525
  • https://github.com/cw-alexcroteau/nx-tsconfig-path-prefix-false-positive-repro-20260525/actions/runs/26414457118

Supersedes closed PR #35786.

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[nx-cloud]

View your CI Pipeline Execution ↗ for commit 8e92584

Command	Status	Duration	Result
nx-cloud record -- nx format:check	❌ Failed	5s	View ↗
nx run-many -t check-imports check-lock-files c...	✅ Succeeded	3s	View ↗
nx-cloud record -- nx sync:check	✅ Succeeded	20s	View ↗

---

☁️ Nx Cloud last updated this comment at 2026-06-12 14:10:26 UTC

[nx-cloud]

Nx Cloud is proposing a fix for your failed CI:

We ran nx format to fix the format:check failure caused by the newly added regression test in tsconfig-json-changes.spec.ts. The long path strings inside the paths object exceeded prettier's print width, requiring the array values to be wrapped onto separate lines. This formatting change brings the file into compliance with the workspace's code style rules.

Tip

✅ We verified this fix by re-running nx-cloud record -- nx format:check.

Suggested Fix changes

diff --git a/packages/nx/src/plugins/js/project-graph/affected/tsconfig-json-changes.spec.ts b/packages/nx/src/plugins/js/project-graph/affected/tsconfig-json-changes.spec.ts
index a7f893c8..1f665881 100644
--- a/packages/nx/src/plugins/js/project-graph/affected/tsconfig-json-changes.spec.ts
+++ b/packages/nx/src/plugins/js/project-graph/affected/tsconfig-json-changes.spec.ts
@@ -335,14 +335,18 @@ describe('getTouchedProjectsFromTsConfig', () => {
                     {
                       compilerOptions: {
                         paths: {
-                          '@proj/cdk-utils': ['libs/typescript/cdk-utils/index.ts'],
+                          '@proj/cdk-utils': [
+                            'libs/typescript/cdk-utils/index.ts',
+                          ],
                         },
                       },
                     },
                     {
                       compilerOptions: {
                         paths: {
-                          '@proj/cdk-utils': ['libs/typescript/cdk-utils/utils.ts'],
+                          '@proj/cdk-utils': [
+                            'libs/typescript/cdk-utils/utils.ts',
+                          ],
                         },
                       },
                     }

Because this branch comes from a fork, it is not possible for us to apply fixes directly, but you can apply the changes locally using the available options below.

Apply changes locally with:

npx nx-cloud apply-locally 1lo6-u1jw

Apply fix locally with your editor ↗   View interactive diff ↗

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