Add FS3888 diagnostic for namespace/type collision

.executor-pid

@@ -0,0 +1 @@
+22280

src/Compiler/FSComp.txt

@@ -1818,4 +1818,5 @@ featurePreprocessorElif,"#elif preprocessor directive"
 3885,parsLetBangCannotBeLastInCE,"'%s' cannot be the final expression in a computation expression. Finish with 'return', 'return!', or a simple expression."
 3886,tcListLiteralWithSingleTupleElement,"This list expression contains a single tuple element. Did you mean to use ';' instead of ',' to separate list elements?"
 3887,ilCustomAttrInvalidArrayElemType,"The type '%s' is not a valid custom attribute argument type. Custom attribute arrays must have elements of primitive types, enums, string, System.Type, or System.Object."
+3888,tastNamespaceAndTypeWithSameNameInAssembly,"The namespace '%s' clashes with the type '%s'."
 featureExceptionFieldSerializationSupport,"emit GetObjectData and field-restoring deserialization constructor for exception types"

src/Compiler/Service/ServiceParsedInputOps.fs

@@ -2602,17 +2602,55 @@ module ParsedInput =
 
         mkPos line ctx.Pos.Column
 
+    let private tryFindLastHashRLineInScript (parsedInput: ParsedInput) =
+        if
+            not (
+                parsedInput.FileName.EndsWith(".fsx", System.StringComparison.OrdinalIgnoreCase)
+                || parsedInput.FileName.EndsWith(".fsscript", System.StringComparison.OrdinalIgnoreCase)
+            )
+        then
+            None
+        else
+            match parsedInput with
+            | ParsedInput.SigFile _ -> None
+            | ParsedInput.ImplFile(ParsedImplFileInput(hashDirectives = fileHashes; contents = contents)) ->
+                let mutable lastLine = 0
+
+                let consider (ParsedHashDirective(ident, _, r)) =
+                    if ident = "r" && r.EndLine > lastLine then
+                        lastLine <- r.EndLine
+
+                fileHashes |> List.iter consider
+
+                let rec walkDecl (decl: SynModuleDecl) =
+                    match decl with
+                    | SynModuleDecl.HashDirective(hashDirective = hd) -> consider hd
+                    | SynModuleDecl.NestedModule(decls = decls) -> List.iter walkDecl decls
+                    | SynModuleDecl.NamespaceFragment(SynModuleOrNamespace(decls = decls)) -> List.iter walkDecl decls
+                    | _ -> ()
+
+                for SynModuleOrNamespace(decls = decls) in contents do
+                    List.iter walkDecl decls
+
+                if lastLine > 0 then Some lastLine else None
+
     let FindNearestPointToInsertOpenDeclaration
         (currentLine: int)
         (parsedInput: ParsedInput)
         (entity: ShortIdents)
         (insertionPoint: OpenStatementInsertionPoint)
         =
-        match tryFindNearestPointAndModules currentLine parsedInput insertionPoint with
-        | Some(scope, _, point), modules -> findBestPositionToInsertOpenDeclaration modules scope point entity
-        | _ ->
-            // we failed to find insertion point because ast is empty for some reason, return top left point in this case
-            {
-                ScopeKind = ScopeKind.TopModule
-                Pos = mkPos 1 0
-            }
+        let ctx =
+            match tryFindNearestPointAndModules currentLine parsedInput insertionPoint with
+            | Some(scope, _, point), modules -> findBestPositionToInsertOpenDeclaration modules scope point entity
+            | _ ->
+                // we failed to find insertion point because ast is empty for some reason, return top left point in this case
+                {
+                    ScopeKind = ScopeKind.TopModule
+                    Pos = mkPos 1 0
+                }
+
+        // For .fsx scripts, ensure the open is placed after any #r directives.
+        match tryFindLastHashRLineInScript parsedInput with
+        | Some lastRLine when ctx.Pos.Line <= lastRLine -> { ctx with Pos = mkPos (lastRLine + 1) 0 }
+        | _ -> ctx

src/Compiler/TypedTree/TypedTreeOps.Remapping.fs

@@ -622,8 +622,11 @@ module internal SignatureOps =
 
             match entity1.IsNamespace, entity2.IsNamespace, entity1.IsModule, entity2.IsModule with
             | true, true, _, _ -> ()
+            | true, _, _, true
+            | _, true, true, _ -> errorR (Error(FSComp.SR.tastNamespaceAndModuleWithSameNameInAssembly (textOfPath path2), entity2.Range))
             | true, _, _, _
-            | _, true, _, _ -> errorR (Error(FSComp.SR.tastNamespaceAndModuleWithSameNameInAssembly (textOfPath path2), entity2.Range))
+            | _, true, _, _ ->
+                errorR (Error(FSComp.SR.tastNamespaceAndTypeWithSameNameInAssembly (textOfPath path2, entity2.LogicalName), entity2.Range))
             | false, false, false, false ->
                 errorR (Error(FSComp.SR.tastDuplicateTypeDefinitionInAssembly (entity2.LogicalName, textOfPath path), entity2.Range))
             | false, false, true, true -> errorR (Error(FSComp.SR.tastTwoModulesWithSameNameInAssembly (textOfPath path2), entity2.Range))