Make Config generator test only for down-casts #106145
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We were hitting compiler errors when the generator emitted test casts for value types. Since those can never be true (value types cannot be derived from, and the compiler can see if the cast will succeed or not). Fix this by only doing a test cast when we are trying to do a runtime downcast.
ericstj
requested review from
eiriktsarpalis,
steveharter,
eerhardt and
tarekgh
...raries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Parser.cs
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...raries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Parser.cs
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src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Specs/Types/CollectionSpec.cs
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...nsions.Configuration.Binder/tests/Common/ConfigurationBinderTests.TestClasses.Collections.cs
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These are unsupported and ignored by the generator and a diagnostic is emitted. Binding data to them does nothing.
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Looks good, although it seems like the flag is only kicking in when predetermined pairs of types are detected. Can the source generator produce casts for types other than these collection types, and if so couldn't the shouldTryCast value be determined in the general case? (i.e. by looking at the subtype relationship between the source and target types)
It's everywhere that
I audited this file for uses of |
| @@ -36,12 +36,12 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration | |||
| { | |||
| #region IConfiguration extensions. | |||
| /// <summary>Attempts to bind the configuration instance to a new instance of type T.</summary> | |||
| [InterceptsLocation(@"src-0.cs", 12, 17)] | |||
| [InterceptsLocation(@"src-0.cs", 13, 17)] | |||
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Good to see this change in the "version 0" baseline - did you encounter any test issues or did you just remember to do this?
Fix #94547
We were hitting compiler errors when the generator emitted test casts for value types. Since those can never be true (value types cannot be derived from, and the compiler can see if the cast will succeed or not).
Fix this by only doing a test cast when we are trying to do a runtime downcast.