Angular SSR + Firebase App Hosting: build fails when importing shared utility functions

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Summary

The issue at hand is an Angular SSR application that fails to build when deploying to Firebase App Hosting due to unresolved imports of shared utility functions. Key Takeaways include understanding how Angular SSR and Firebase App Hosting interact, and how to properly configure imports for shared functions.

Root Cause

The root cause of this issue lies in the way Angular SSR resolves imports during the build process for server-side rendering. The main causes are:

  • Incorrect path resolution for shared utility functions
  • Missing configuration for server-side rendering in angular.json or tsconfig.json
  • Inadequate understanding of how Firebase App Hosting handles Angular SSR builds

Why This Happens in Real Systems

This issue occurs in real systems due to:

  • Misconfigured paths in import statements
  • Inadequate server-side rendering setup in Angular projects
  • Lack of understanding of how different environments (local vs. production) handle imports and builds
  • Insufficient testing of deployment configurations before pushing to production

Real-World Impact

The real-world impact of this issue includes:

  • Failed deployments to Firebase App Hosting
  • Increased downtime due to prolonged debugging and troubleshooting
  • Decreased developer productivity spent on resolving environment-specific issues rather than feature development
  • Potential security risks if temporary workarounds compromise application security

Example or Code

// Example of a shared utility function
export function enumValues(e: T): string[] {
  return Object.keys(e);
}
// Example of tsconfig.json configuration for Angular SSR
{
  "compilerOptions": {
    // ... other options ...
    "paths": {
      "@app/*": ["src/app/*"],
      "@shared/*": ["src/app/shared/*"]
    }
  }
}

How Senior Engineers Fix It

Senior engineers fix this issue by:

  • Reviewing import paths and ensuring they are correctly resolved for both local development and production environments
  • Configuring angular.json and tsconfig.json to properly handle server-side rendering and shared utility functions
  • Implementing environment-specific configurations to account for differences between local and production builds
  • Thoroughly testing deployment configurations before pushing to production

Why Juniors Miss It

Junior engineers might miss this issue due to:

  • Lack of experience with Angular SSR and Firebase App Hosting
  • Insufficient understanding of how imports are resolved in different environments
  • Inadequate testing of deployment configurations
  • Overlooking the importance of properly configuring angular.json and tsconfig.json for server-side rendering and shared utility functions