Anonymous type accros assembly

[oli-unreal]

Description

I don't know if it is a bug or the doc that doesn't make it obvious. If I create 2 anonymous objects in 2 assemblies, the equals is always false, but the obj1.ToString().Equals(obj2.ToString()) returns true.

After reading the doc multiple times, it may be the expected behaviour:

If two or more anonymous object initializers in an assembly specify a sequence of properties that are in the same order and that have the same names and types, the compiler treats the objects as instances of the same type. They share the same compiler-generated type information.

And several paragraphs below:

Because the Equals and GetHashCode methods on anonymous types are defined in terms of the Equals and GetHashCode methods of the properties, two instances of the same anonymous type are equal only if all their properties are equal.

I think the same anonymous type should be more explicit especially when we are talking about comparison. It should at least said that it is required to be in the same assembly.

Reproduction Steps

I created an anonymous object to post a JSON via PostAsJsonAsync and in the test assembly with Moq I wanted to intercept the call with the right object.

Expected behavior

Anonymous objects should be equal if all their properties are equal regardless of the assembly it is created on.

Actual behavior

Comparison requires to be on the same assembly.

Regression?

No

Known Workarounds

Use string to do the comparison...
obj1.ToString().Equals(obj2.ToString())

Configuration

.Net 7, x64

---

Document Details

⚠ Do not edit this section. It is required for learn.microsoft.com ➟ GitHub issue linking.

• ID: d1b30ebe-b640-449b-3602-9891a55794db
• Version Independent ID: dd937177-98f0-a797-d49b-29332aae0614
• Content: Anonymous Types - C#
• Content Source: docs/csharp/fundamentals/types/anonymous-types.md
• Product: dotnet-csharp
• Technology: csharp-fundamentals
• GitHub Login: @BillWagner
• Microsoft Alias: wiwagn

[gfoidl]

Is

in an assembly

not explicit enough?
It seems you confused it with "any assembly"? (that part of the docs could be re-typed to make that more obvious, right)

[oli-unreal]

The in an assembly is 4 paragraphs above where the Equals is described. If you focus on Equal paragraph, which I did because it is what I was interested in, it doesn't talk about assembly. You have to read the whole document and make the link between multiple paragraphs. If the text was like this:

Because the Equals and GetHashCode methods on anonymous types are defined in terms of the Equals and GetHashCode methods of the properties, on the same assembly, two instances of the same anonymous type are equal only if all their properties are equal.
or
Because the Equals and GetHashCode methods on anonymous types are defined in terms of the Equals and GetHashCode methods of the properties, two instances of the same anonymous type are equal only if all their properties are equal. Anonymous objects from different assemblies cannot be Equals, since there are not the same type.

[gfoidl]

@gewarren can you move this issue to dotnet/docs please?
(I hope you are the right person to tag)

[BillWagner]

The doc infers the behavior, but we should make it clear by stating that anonymous types have internal accessibility.

This would make it more clear that types with the same "shape" but defined in different assemblies aren't the same type. Therefore instances of those two types can't be equal to each other.

[Earthman100]

Is

in an assembly

not explicit enough? It seems you confused it with "any assembly"? (that part of the docs could be re-typed to make that more obvious, right)

.32 of -1.075 path semvers #definition prolly svg init to selector of .8@.08009 in infunvt showing .8008 or 1.00900090000999 to prevent byte errors on E- binds to offline source references to referers origin of meta link