Automatic generation of ConfigurationSchema.json files

[eerhardt]

Today, each Aspire Component has a ConfigurationSchema.json file that is added to the nupkg to provide JSON intellisense in appsettings.json files in the IDE:

aspire/src/Components/Aspire.StackExchange.Redis/ConfigurationSchema.json

Lines 21 to 32 in a3f058c

	"ConfigurationOptions": {
	"type": "object",
	"description": "The options relevant to a set of redis connections.",
	"properties": {
	"AbortOnConnectFail": {
	"type": "boolean",
	"description": "Gets or sets whether connect/configuration timeouts should be explicitly notified via a TimeoutException."
	},
	"AllowAdmin": {
	"type": "boolean",
	"description": "Indicates whether admin operations should be allowed."
	},

Currently these .json files are hand-crafted. We should be able to generate them. My high-level thinking is:

• Add a "post-compile" task to the build that uses Roslyn APIs to inspect and generate these .json files based on a supplied set of Types and config paths.
  • Note that this can't be a "normal" source generator because Roslyn doesn't support generating non-C# files.
• The ConfigurationSchema.json files stay checked into source control
  • This allows us to inspect, link to, and see the history of the file over time.
• If the generated file is different than the checked-in file, fail the build.
• The generator has an MSBuild option to overwrite the file, so when it needs to be updated you can simply dotnet build /p:UpdateConfigurationSchema=true and produce the new file

[eerhardt]

Another reason this tool can't be a Roslyn source generator is because it needs to read XML docs for referenced assemblies. For example, the ConfigurationOptions.AllowAdmin property above gets its description from the XML docs on the StackExchange.Redis ConfigurationOptions type. A Roslyn source generator can't get this information due to dotnet/roslyn#51769.