Enable strictPeerDependencies in Rush with globalPeerDependencyRules for known upstream issues

[nick-pape]

Summary

The Rush pnpm-config.json currently has strictPeerDependencies: false to work around upstream peer dependency issues in Microsoft's SPFx packages. This should be changed to strictPeerDependencies: true with appropriate globalPeerDependencyRules to suppress the known upstream issues, so that any new peer dependency problems are caught immediately.

Current State

In common/config/rush/pnpm-config.json:

"strictPeerDependencies": false,

This silently ignores all peer dependency issues, including any new ones introduced by future dependency changes.

Proposed Change

Enable strict peer dependencies and add rules to suppress the known upstream issues:

"strictPeerDependencies": true,

"globalPeerDependencyRules": {
  "ignoreMissing": [
    "swiper",
    "scheduler",
    "@microsoft/microsoft-graph-client"
  ],
  "allowedVersions": {
    "@rushstack/heft": ">=0.71.1"
  }
}

Why This Matters

With strictPeerDependencies: false, any new unmet peer dependency introduced by a dependency upgrade will be silently ignored. This can lead to:

• Runtime errors that are hard to diagnose
• Version conflicts that go unnoticed
• Subtle bugs from incompatible dependency versions

With strictPeerDependencies: true + targeted suppression rules, the known upstream issues are documented and suppressed, while any new peer dependency problems will cause rush update to fail — catching issues early.

Related Issues

• Missing peer dependency: swiper@^8.2.6 required by adaptivecards (via @microsoft/sp-adaptive-card-extension-base) #73 — Missing peer: swiper@^8.2.6 (from adaptivecards)
• Missing peer dependency: scheduler@>=0.19.0 required by @fluentui/react-context-selector (via @microsoft/sp-component-base) #74 — Missing peer: scheduler@>=0.19.0 (from @fluentui/react-context-selector)
• Unmet peer dependency: @microsoft/microsoft-graph-client@3.0.2 required but 1.7.2-spfx is installed #75 — Unmet peer: @microsoft/microsoft-graph-client@3.0.2 (version mismatch)
• Unmet peer dependency: @rushstack/heft@^0.71.1 required by heft-sass-plugin but 1.1.2 is installed #76 — Unmet peer: @rushstack/heft@^0.71.1 (version mismatch in build rig)