Root cause:
- A trailing comma inside a generic argument list can produce an empty generic argument, for example:
`OrderedDictionary<String, (status: Result<Int, Error>, messages: [String]),>`
- During composition, `ParserResultsComposed.resolveType` force-unwrapped
`typeName.name.split(separator: " ").first!` when generic requirements were present.
- If the generic parameter was empty, this force unwrap crashed with
`Unexpectedly found nil while unwrapping an Optional value`.
What changed:
- Hardened `ParserResultsComposed.resolveType` to skip generic-requirement lookup
when the lookup token is empty (no force unwrap).
- Filtered out empty/whitespace generic arguments in SwiftSyntax parsing
(`GenericType+SwiftSyntax`).
- Filtered out empty/whitespace generic arguments in string-based type inference
(`String+TypeInference`).
- Added a regression spec in `ComposerSpec` that covers a constrained generic type
containing a trailing comma in a generic argument list and asserts only two valid
generic parameters are produced.
Repro script:
```bash
cat > /tmp/Repro.swift <<'SWIFT'
struct Example<A: RandomAccessCollection, B: RandomAccessCollection>
where A.Element == String,
B.Element == String
{
let asyncTaskData: OrderedDictionary<
String,
(status: Result<Int, Error>, messages: [String]),
>
}
SWIFT
cat > /tmp/inspect.stencil <<'STENCIL'
{% for type in types.structs %}
{% for variable in type.variables %}
{% if variable.name == "asyncTaskData" and variable.typeName.generic %}
GENERIC_COUNT={{ variable.typeName.generic.typeParameters.count }}
{% for p in variable.typeName.generic.typeParameters %}
PARAM={{ p.typeName.name }}
{% endfor %}
{% endif %}
{% endfor %}
{% endfor %}
STENCIL
# Before this fix: crashes with Trace/BPT trap.
# After this fix:
# GENERIC_COUNT=2
# PARAM=String
# PARAM=(status: Result<Int, Error>, messages: [String])
sourcery --disableCache --sources /tmp/Repro.swift --templates /tmp/inspect.stencil --output /tmp/out.txt
cat /tmp/out.txt
```
Creates and re-use a static JSVirtualMachine when rendering EJS templates so watch mode doesn't break when old JSContext deallocate and deadlock the main thread.
Krzysztof Zabłocki
NachoSoto
Igor Skovorodkin
Maksym Musiienko
Eric Horacek
Lars
Benedek Kozma
Max
Robert Payne
swiftty
r3econ
Rafal Sroka
r3econ