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Diffstat (limited to 'tvix/eval/src/builtins/mod.rs')
-rw-r--r-- | tvix/eval/src/builtins/mod.rs | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/tvix/eval/src/builtins/mod.rs b/tvix/eval/src/builtins/mod.rs index e19de961588d..a9d04ba7c3fb 100644 --- a/tvix/eval/src/builtins/mod.rs +++ b/tvix/eval/src/builtins/mod.rs @@ -359,6 +359,15 @@ mod pure_builtins { #[builtin("toJSON")] async fn builtin_to_json(co: GenCo, val: Value) -> Result<Value, ErrorKind> { + if let Value::Attrs(attrs) = &val { + // Attribute sets with a callable `__toString` attribute + // serialise to the string-coerced version of the result of + // calling that. + if let Some(s) = attrs.try_to_string(&co, CoercionKind::Weak).await { + return Ok(Value::String(serde_json::to_string(&s)?.into())); + } + } + // All thunks need to be evaluated before serialising, as the // data structure is fully traversed by the Serializer. let val = generators::request_deep_force(&co, val, SharedThunkSet::default()).await; |