Draft: Fix tests (#23)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **New Features**
- Enhanced flexibility in the `Overwrite` function by allowing implicit
type conversion for the `value` argument.
  
- **Bug Fixes**
- Updated type constraints in `Overwrite` constructor to ensure better
compatibility and error handling.

- **Tests**
- Adjusted test cases to align with updated type constraints, improving
overall test accuracy.
  
- **Refactor**
- Refined type restrictions in various function calls and declarations
for improved code clarity and performance.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

src/Overwrite.jl

@@ -42,6 +42,7 @@ julia> deserialize(Overwrite(UInt8, 0x01), b"\\x05")
 ```
 """
 Overwrite(subcon::Construct{T}, value::T) where {T} = Overwrite(subcon, ((obj; contextkw...) -> value))
+Overwrite(subcon::Construct{T}, value) where {T} = Overwrite(subcon, ((obj; contextkw...) -> convert(T, value)))
 Overwrite(::Type{T}, getter) where {T} = Overwrite(Construct(T), getter)
 
 encode(cons::Overwrite{T, TSubCon, GT}, obj::T; contextkw...) where {T, TSubCon, GT<:Function} = convert(T, apply_optional_contextkw(cons.getter, obj, contextkw))

test/runtests.jl

@@ -394,8 +394,8 @@ end
     @testset "Overwrite" begin
         @testset "deduce type" begin
             @test Constructs.deducetype((v) -> Overwrite(UInt8, v), UInt8) <: Construct{UInt8}
-            @test Constructs.deducetype((v) -> Overwrite(UInt8, v), Function) <: Construct{UInt8}
-            @test Constructs.deducetype((v) -> Overwrite(UInt8, v), UndefProperty) <: Construct{UInt8}
+            @test Constructs.deducetype((v) -> Overwrite(Int8, v), typeof(abs)) <: Construct{Int8}
+            @test Constructs.deducetype((v) -> Overwrite(UInt8, v), UndefProperty{UInt8}) <: Construct{UInt8}
         end
         @test_throws ArgumentError Overwrite(UInt8, () -> 0x01)
         @test serialize(Overwrite(UInt8, 0x01), 2) == b"\x01"
@@ -643,17 +643,17 @@ end
         withoverwrite = quote
             @construct struct Bitmap <: AbstractImage
                 signature::Const(b"BMP")
-                width::Overwrite(UInt32, convert(UInt32, size(this.pixel, 2)))
-                height::Overwrite(UInt32, convert(UInt32, size(this.pixel, 1)))
+                width::Overwrite(UInt32, _ -> convert(UInt32, size(this.pixel, 2)))
+                height::Overwrite(UInt32, _ -> convert(UInt32, size(this.pixel, 1)))
                 ::Padded(8)
                 pixel::SizedArray(UInt8, this.height, this.width)
             end
         end
         withhidden = quote
             @construct struct Bitmap <: AbstractImage
                 [signature]::Const(b"BMP")
-                [width]::Overwrite(UInt32, convert(UInt32, size(this.pixel, 2)))
-                [height]::Overwrite(UInt32, convert(UInt32, size(this.pixel, 1)))
+                [width]::Overwrite(UInt32, _ -> convert(UInt32, size(this.pixel, 2)))
+                [height]::Overwrite(UInt32, _ -> convert(UInt32, size(this.pixel, 1)))
                 ::Padded(8)
                 pixel::SizedArray(UInt8, this.height, this.width)
             end