diff --git a/test/FsAutoComplete.Tests.Lsp/DecompilerTests.fs b/test/FsAutoComplete.Tests.Lsp/DecompilerTests.fs
new file mode 100644
index 000000000..b3ea200d1
--- /dev/null
+++ b/test/FsAutoComplete.Tests.Lsp/DecompilerTests.fs
@@ -0,0 +1,101 @@
+module FsAutoComplete.Tests.Lsp.DecompilerTests
+
+open Expecto
+open FsAutoComplete.Decompiler
+open FSharp.Compiler.Text
+
+/// Tests for the Decompiler module utility functions
+module DecompilerTests =
+
+  /// Tests for file name sanitization
+  let fileNameSanitizationTests =
+    testList "File Name Sanitization" [
+      
+      testCase "toSafeFileNameRegex compilation" <| fun _ ->
+        // Test that the regex compiles and works on basic unsafe characters
+        let regex = toSafeFileNameRegex
+        let testInput = "test<>file"
+        let result = regex.Replace(testInput, "_")
+        Expect.equal result "test__file" "Should replace unsafe characters with underscores"
+        
+      testCase "handles multiple unsafe characters" <| fun _ ->
+        let regex = toSafeFileNameRegex
+        let testInput = "test|file:name?"
+        let result = regex.Replace(testInput, "_")
+        Expect.equal result "test_file_name_" "Should replace all unsafe characters"
+        
+      testCase "leaves safe characters unchanged" <| fun _ ->
+        let regex = toSafeFileNameRegex
+        let testInput = "SafeFileName123.cs"
+        let result = regex.Replace(testInput, "_")
+        Expect.equal result "SafeFileName123.cs" "Should leave safe characters unchanged"
+    ]
+
+  /// Tests for type accessibility and compilation
+  let typeAccessibilityTests =
+    testList "Type Accessibility Tests" [
+      
+      testCase "DecompileError type is accessible" <| fun _ ->
+        let decompileErrorType = typeof<DecompileError>
+        Expect.isNotNull decompileErrorType "DecompileError type should be accessible"
+        
+      testCase "ExternalContentPosition type is accessible" <| fun _ ->
+        let externalContentPositionType = typeof<ExternalContentPosition>
+        Expect.isNotNull externalContentPositionType "ExternalContentPosition type should be accessible"
+        
+      testCase "FindExternalDeclarationError type is accessible" <| fun _ ->
+        let errorType = typeof<FindExternalDeclarationError>
+        Expect.isNotNull errorType "FindExternalDeclarationError type should be accessible"
+    ]
+
+  /// Tests for ExternalContentPosition record structure
+  let externalContentPositionTests =
+    testList "ExternalContentPosition Tests" [
+      
+      testCase "ExternalContentPosition record construction" <| fun _ ->
+        let pos = Position.fromZ 10 5
+        let position: ExternalContentPosition = {
+          File = "test.cs"
+          Position = pos
+        }
+        
+        Expect.equal position.File "test.cs" "Should set file correctly"
+        Expect.equal position.Position.Line 10 "Should set position line correctly"
+        Expect.equal position.Position.Column 5 "Should set position column correctly"
+        
+      testCase "ExternalContentPosition with empty file" <| fun _ ->
+        let pos = Position.fromZ 0 0
+        let position: ExternalContentPosition = {
+          File = ""
+          Position = pos
+        }
+        
+        Expect.equal position.File "" "Should handle empty file name"
+        Expect.equal position.Position.Line 0 "Should handle zero position"
+    ]
+
+  /// Tests for module compilation and function accessibility
+  let moduleAccessibilityTests =
+    testList "Module Accessibility Tests" [
+      
+      testCase "core functions exist" <| fun _ ->
+        // Use reflection to verify the function exists and is accessible
+        let decompilerModule = typeof<DecompileError>.DeclaringType
+        
+        let decompilerForFileMethod = decompilerModule.GetMethod("decompilerForFile")
+        Expect.isNotNull decompilerForFileMethod "decompilerForFile function should exist"
+        
+        let decompileMethod = decompilerModule.GetMethod("decompile")
+        Expect.isNotNull decompileMethod "decompile function should exist"
+        
+        let tryFindMethod = decompilerModule.GetMethod("tryFindExternalDeclaration")
+        Expect.isNotNull tryFindMethod "tryFindExternalDeclaration function should exist"
+    ]
+
+let tests = 
+  testList "Decompiler Tests" [
+    DecompilerTests.fileNameSanitizationTests
+    DecompilerTests.typeAccessibilityTests
+    DecompilerTests.externalContentPositionTests
+    DecompilerTests.moduleAccessibilityTests
+  ]
\ No newline at end of file
diff --git a/test/FsAutoComplete.Tests.Lsp/Program.fs b/test/FsAutoComplete.Tests.Lsp/Program.fs
index 6736ea79a..65e5e8465 100644
--- a/test/FsAutoComplete.Tests.Lsp/Program.fs
+++ b/test/FsAutoComplete.Tests.Lsp/Program.fs
@@ -12,6 +12,9 @@ open FsAutoComplete.Tests.ScriptTest
 open FsAutoComplete.Tests.ExtensionsTests
 open FsAutoComplete.Tests.InteractiveDirectivesTests
 open FsAutoComplete.Tests.Lsp.CoreUtilsTests
+open FsAutoComplete.Tests.Lsp.SourcelinkTests
+open FsAutoComplete.Tests.Lsp.DecompilerTests
+open FsAutoComplete.Tests.Lsp.RecordStubGeneratorTests
 open Ionide.ProjInfo
 open System.Threading
 open Serilog.Filters
@@ -143,6 +146,9 @@ let lspTests =
 let generalTests = testList "general" [
   testList (nameof (Utils)) [ Utils.Tests.Utils.tests; Utils.Tests.TextEdit.tests ]
   UtilsTests.allTests
+  FsAutoComplete.Tests.Lsp.SourcelinkTests.tests
+  FsAutoComplete.Tests.Lsp.DecompilerTests.tests
+  FsAutoComplete.Tests.Lsp.RecordStubGeneratorTests.tests
   InlayHintTests.explicitTypeInfoTests sourceTextFactory
   FindReferences.tryFixupRangeTests sourceTextFactory
 ]
diff --git a/test/FsAutoComplete.Tests.Lsp/RecordStubGeneratorTests.fs b/test/FsAutoComplete.Tests.Lsp/RecordStubGeneratorTests.fs
new file mode 100644
index 000000000..1c8bb32a2
--- /dev/null
+++ b/test/FsAutoComplete.Tests.Lsp/RecordStubGeneratorTests.fs
@@ -0,0 +1,115 @@
+module FsAutoComplete.Tests.Lsp.RecordStubGeneratorTests
+
+open Expecto
+open FsAutoComplete.RecordStubGenerator
+open FSharp.Compiler.Text
+
+/// Tests for the RecordStubGenerator module
+module RecordStubGeneratorTests =
+
+  /// Tests for PositionKind enumeration and basic types
+  let positionKindTests =
+    testList "PositionKind Tests" [
+      
+      testCase "PositionKind cases are defined" <| fun _ ->
+        // Test that all position kind cases are accessible
+        let _afterLeftBrace = PositionKind.AfterLeftBrace
+        let _afterCopyExpression = PositionKind.AfterCopyExpression  
+        let _afterLastField = PositionKind.AfterLastField
+        
+        Expect.isTrue true "AfterLeftBrace should be defined"
+        Expect.isTrue true "AfterCopyExpression should be defined"
+        Expect.isTrue true "AfterLastField should be defined"
+        
+      testCase "PositionKind pattern matching works" <| fun _ ->
+        let testKind = PositionKind.AfterLeftBrace
+        
+        let result = 
+          match testKind with
+          | PositionKind.AfterLeftBrace -> "after brace"
+          | PositionKind.AfterCopyExpression -> "after copy"
+          | PositionKind.AfterLastField -> "after field"
+          
+        Expect.equal result "after brace" "Pattern matching should work correctly"
+    ]
+
+  /// Tests for RecordStubsInsertionParams type and construction
+  let insertionParamsTests =
+    testList "RecordStubsInsertionParams Tests" [
+      
+      testCase "RecordStubsInsertionParams construction" <| fun _ ->
+        let pos = Position.fromZ 5 10
+        let insertionParams = {
+          Kind = PositionKind.AfterLeftBrace
+          InsertionPos = pos
+          IndentColumn = 4
+        }
+        
+        Expect.equal insertionParams.Kind PositionKind.AfterLeftBrace "Kind should be set correctly"
+        Expect.equal insertionParams.InsertionPos.Line 5 "Position line should be set correctly"  
+        Expect.equal insertionParams.InsertionPos.Column 10 "Position column should be set correctly"
+        Expect.equal insertionParams.IndentColumn 4 "IndentColumn should be set correctly"
+    ]
+
+  /// Tests for RecordExpr type accessibility
+  let recordExprTests =
+    testList "RecordExpr Tests" [
+      
+      testCase "RecordExpr type structure" <| fun _ ->
+        // Test that we can access the RecordExpr type and its fields
+        let recordExprType = typeof<RecordExpr>
+        Expect.isNotNull recordExprType "RecordExpr type should be accessible"
+        
+        // Check that the required fields exist
+        let exprField = recordExprType.GetProperty("Expr")
+        let copyExprField = recordExprType.GetProperty("CopyExprOption")
+        let fieldExprListField = recordExprType.GetProperty("FieldExprList") 
+        let lastKnownPosField = recordExprType.GetProperty("LastKnownGoodPosForSymbolLookup")
+        
+        Expect.isNotNull exprField "Expr field should exist"
+        Expect.isNotNull copyExprField "CopyExprOption field should exist"
+        Expect.isNotNull fieldExprListField "FieldExprList field should exist"
+        Expect.isNotNull lastKnownPosField "LastKnownGoodPosForSymbolLookup field should exist"
+    ]
+
+  /// Tests for module compilation and function accessibility
+  let moduleAccessibilityTests =
+    testList "Module Accessibility Tests" [
+      
+      testCase "key functions exist" <| fun _ ->
+        // Use reflection to verify the function exists and is accessible
+        let moduleType = typeof<RecordExpr>.DeclaringType
+        
+        let formatRecordMethod = moduleType.GetMethod("formatRecord")
+        Expect.isNotNull formatRecordMethod "formatRecord function should exist and be accessible"
+        
+        let tryFindRecordExprMethod = moduleType.GetMethod("tryFindRecordExprInBufferAtPos")
+        Expect.isNotNull tryFindRecordExprMethod "tryFindRecordExprInBufferAtPos function should exist"
+        
+        let shouldGenerateMethod = moduleType.GetMethod("shouldGenerateRecordStub")
+        Expect.isNotNull shouldGenerateMethod "shouldGenerateRecordStub function should exist"
+    ]
+
+  /// Tests for Position integration
+  let positionTests =
+    testList "Position Integration Tests" [
+      
+      testCase "Position creation and usage" <| fun _ ->
+        // Test Position utility functions used in the module
+        let pos1 = Position.fromZ 10 5
+        let pos2 = Position.fromZ 10 5  
+        let pos3 = Position.fromZ 11 5
+        
+        Expect.equal pos1.Line pos2.Line "Same positions should have same line"
+        Expect.equal pos1.Column pos2.Column "Same positions should have same column"
+        Expect.notEqual pos1.Line pos3.Line "Different positions should have different line"
+    ]
+
+let tests = 
+  testList "RecordStubGenerator Tests" [
+    RecordStubGeneratorTests.positionKindTests
+    RecordStubGeneratorTests.insertionParamsTests
+    RecordStubGeneratorTests.recordExprTests
+    RecordStubGeneratorTests.moduleAccessibilityTests
+    RecordStubGeneratorTests.positionTests
+  ]
\ No newline at end of file
diff --git a/test/FsAutoComplete.Tests.Lsp/SourcelinkTests.fs b/test/FsAutoComplete.Tests.Lsp/SourcelinkTests.fs
new file mode 100644
index 000000000..20cc9d8e7
--- /dev/null
+++ b/test/FsAutoComplete.Tests.Lsp/SourcelinkTests.fs
@@ -0,0 +1,65 @@
+module FsAutoComplete.Tests.Lsp.SourcelinkTests
+
+open Expecto
+open FsAutoComplete.Sourcelink
+
+/// Tests for the Sourcelink module functions that are accessible
+module SourcelinkTests =
+
+  /// Tests for module compilation and basic accessibility  
+  let basicAccessibilityTests =
+    testList "Basic Accessibility Tests" [
+      
+      testCase "Sourcelink module compiles and is accessible" <| fun _ ->
+        // Test that the module compiles and key types are accessible
+        let sourceLinkJsonType = typeof<SourceLinkJson>
+        Expect.isNotNull sourceLinkJsonType "SourceLinkJson type should be accessible"
+        
+      testCase "Errors type is accessible" <| fun _ ->
+        let errorsType = typeof<Errors>
+        Expect.isNotNull errorsType "Errors type should be accessible"
+        
+      testCase "key functions exist via reflection" <| fun _ ->
+        // Use reflection to verify key functions exist
+        let sourceLinkJsonType = typeof<SourceLinkJson>
+        let moduleType = sourceLinkJsonType.DeclaringType
+        
+        let tryFetchMethod = moduleType.GetMethod("tryFetchSourcelinkFile")
+        Expect.isNotNull tryFetchMethod "tryFetchSourcelinkFile function should exist"
+    ]
+
+  /// Tests for error types
+  let errorTests =
+    testList "Error Type Tests" [
+      
+      testCase "Basic error cases are accessible" <| fun _ ->
+        // Test that basic error cases can be constructed
+        let _noInfoError = Errors.NoInformation
+        let _invalidJsonError = Errors.InvalidJson
+        let _missingSourceError = Errors.MissingSourceFile
+        let _missingPatternsError = Errors.MissingPatterns
+        
+        Expect.isTrue true "NoInformation error should be accessible"
+        Expect.isTrue true "InvalidJson error should be accessible"  
+        Expect.isTrue true "MissingSourceFile error should be accessible"
+        Expect.isTrue true "MissingPatterns error should be accessible"
+        
+      testCase "Error pattern matching works" <| fun _ ->
+        let testError error =
+          match error with
+          | Errors.NoInformation -> "no-info"
+          | Errors.InvalidJson -> "invalid-json"
+          | Errors.MissingSourceFile -> "missing-source"
+          | Errors.MissingPatterns -> "missing-patterns"
+        
+        Expect.equal (testError Errors.NoInformation) "no-info" "NoInformation pattern should match"
+        Expect.equal (testError Errors.InvalidJson) "invalid-json" "InvalidJson pattern should match"
+        Expect.equal (testError Errors.MissingSourceFile) "missing-source" "MissingSourceFile pattern should match"
+        Expect.equal (testError Errors.MissingPatterns) "missing-patterns" "MissingPatterns pattern should match"
+    ]
+
+let tests = 
+  testList "Sourcelink Tests" [
+    SourcelinkTests.basicAccessibilityTests
+    SourcelinkTests.errorTests
+  ]
\ No newline at end of file