Add apphosting config interface to common.

[annajowang]

• Add interfaces for the apphosting config, while sharing what can be shared with the bundle config
• remove unused and duplicate interfaces in adapter-angular
• Add 'Build' enum value for envvars availability. This was previously limited to "Runtime" because it was used only for bundle.yaml's envvars which are envvars set by the adapter after a build to be used for runtime. Now the envvars interface will be shared with the apphosting config

[gemini-code-assist]

Summary of Changes

Hello @annajowang, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request refactors and centralizes core app hosting configuration interfaces by migrating them from the @apphosting/adapter-angular package to the @apphosting/common package. The primary goal is to establish a unified and reusable configuration schema that can be leveraged across various app hosting frameworks. Key changes include the introduction of a comprehensive ApphostingConfig interface to define runtime, environment variable, and script configurations, and the expansion of environment variable availability to include build-time options.

Highlights

• Centralized Configuration: This pull request centralizes configuration interfaces by moving EnvironmentVariable, Availability, and Metadata from the Angular adapter to the @apphosting/common package. This promotes a unified and reusable configuration schema across different app hosting adapters.
• New Apphosting Configuration Structure: A new ApphostingConfig interface has been introduced in @apphosting/common. This interface serves as the top-level configuration for app hosting, encompassing settings for runtime (runconfig), environment variables (env), and build/run scripts (scripts).
• Enhanced Environment Variable Availability: The Availability enum has been extended to include a Build option. This enhancement allows for environment variables to be configured not only for runtime but also for build processes, providing greater flexibility in application deployment.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point in your pull request via creating an issue comment (i.e. comment on the pull request page) using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in issue comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request centralizes configuration interfaces into the @apphosting/common package, which is a good refactoring. However, I've found a few critical issues with the new interfaces. Some are not exported, which will lead to build failures for consumers of the package, and there's a typing error in EnvVarConfig. I've also included a minor style suggestion for consistency. Addressing these issues will make the new interfaces robust and correct.

[gemini-code-assist]

The OutputFiles interface is used in the exported interfaces OutputBundleConfig and ApphostingConfig, but it's not exported itself. This will cause a TypeScript error for consumers of this package. Please export it. Note that the ServerApp interface used within OutputFiles will also need to be exported for the same reason.

Suggested change

	interface OutputFiles {
	export interface OutputFiles {

[gemini-code-assist]

The type Availability.Runtime[] is too restrictive as it only allows for the value "RUNTIME". To allow for all values from the Availability enum (including "BUILD"), this type should be Availability[].

Suggested change

	availability: Availability.Runtime[];
	availability: Availability[];

[gemini-code-assist]

For consistency with other interface definitions in this file, please add a space before the opening brace.

Suggested change

	export interface ApphostingRunConfig{
	export interface ApphostingRunConfig {