diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 2b96dc1..5fa3b08 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -3,10 +3,10 @@ name: E2E and Unit tests
 on:
   pull_request:
     branches:
-      - master
+      - main
   push:
     branches:
-      - master
+      - main
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -25,7 +25,6 @@ jobs:
         os:
           - windows-latest
           - ubuntu-latest
-          - macos-latest
     steps:
       - name: Fetch Sources
         uses: actions/checkout@v4
@@ -44,11 +43,20 @@ jobs:
           node-version: 22.x
           cache: "yarn"
 
+      - name: Setup EMSDK
+        uses: mymindstorm/setup-emsdk@v14
+        with:
+          version: 3.1.54
+          actions-cache-folder: "emsdk-cache"
+
       - name: Install dependencies
         env:
           YARN_ENABLE_HARDENED_MODE: false
         run: yarn install --immutable
 
+      - name: Build WASM
+        run: yarn grammar:wasm
+
       - name: Build Extension
         run: yarn build
 
@@ -62,3 +70,11 @@ jobs:
       - name: Run e2e tests
         if: matrix.os != 'ubuntu-latest'
         run: yarn run test:e2e
+
+      - name: Upload Language Server Logs
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: language-server-logs-${{ matrix.os }}
+          path: dist/ton-language-server.log
+          if-no-files-found: ignore
diff --git a/package.json b/package.json
index 7ce90f2..5a4d17b 100644
--- a/package.json
+++ b/package.json
@@ -41,7 +41,7 @@
         "lint": "eslint --cache .",
         "fmt": "prettier --write -l --cache .",
         "fmt:check": "prettier --check --cache .",
-        "grammar:wasm": "yarn grammar:tolk:wasm && yarn grammar:fift:wasm && yarn grammar:tlb:wasm",
+        "grammar:wasm": "yarn grammar:tolk:wasm && yarn grammar:func:wasm && yarn grammar:fift:wasm && yarn grammar:tlb:wasm",
         "grammar:tolk:wasm": "cd server/src/languages/tolk/tree-sitter-tolk && tree-sitter generate && tree-sitter build --wasm",
         "grammar:func:wasm": "cd server/src/languages/func/tree-sitter-func && tree-sitter generate && tree-sitter build --wasm",
         "grammar:fift:wasm": "cd server/src/languages/fift/tree-sitter-fift && tree-sitter generate && tree-sitter build --wasm",
diff --git a/server/src/e2e/runTolkTest.ts b/server/src/e2e/runTolkTest.ts
index 7a1cd42..816a6cd 100644
--- a/server/src/e2e/runTolkTest.ts
+++ b/server/src/e2e/runTolkTest.ts
@@ -2,6 +2,7 @@
 //  Copyright © 2025 TON Studio
 import * as path from "node:path"
 import {runTests} from "@vscode/test-electron"
+import {mkdirSync} from "node:fs"
 
 // eslint-disable-next-line functional/type-declaration-immutability
 interface TestRunOptions {
@@ -112,6 +113,14 @@ async function main(): Promise<void> {
         const extensionTestsPath = path.resolve(__dirname, "./out/tolk/index.js")
         const testWorkspace = path.resolve(__dirname, "../../../test-workspace")
 
+        mkdirSync(testWorkspace, {recursive: true})
+
+        if (options.verbose) {
+            console.log("  extensionDevelopmentPath:", extensionDevelopmentPath)
+            console.log("  extensionTestsPath:", extensionTestsPath)
+            console.log("  testWorkspace:", testWorkspace)
+        }
+
         await runTests({
             extensionDevelopmentPath,
             extensionTestsPath,
diff --git a/server/src/e2e/tolk/documentation.test.ts b/server/src/e2e/tolk/documentation.test.ts
index 3ec4cdb..10338ce 100644
--- a/server/src/e2e/tolk/documentation.test.ts
+++ b/server/src/e2e/tolk/documentation.test.ts
@@ -63,6 +63,7 @@ suite("Documentation Test Suite", () => {
                     .trim()
                     .replace(this.workingDir(), "<working-dir>")
                     .replace(workingDir, "<working-dir>")
+                    .replace(/\\/g, "/")
 
                 const expected = testCase.expected
                     .split("\n")
diff --git a/server/src/e2e/tolk/multifile-resolving.test.ts b/server/src/e2e/tolk/multifile-resolving.test.ts
index 9e839b8..d7a370a 100644
--- a/server/src/e2e/tolk/multifile-resolving.test.ts
+++ b/server/src/e2e/tolk/multifile-resolving.test.ts
@@ -56,12 +56,12 @@ suite("Multi file Resolve Test Suite", () => {
                     if (target instanceof vscode.Location) {
                         return `${this.formatLocation(pos)} -> ${this.formatLocation(
                             target.range.start,
-                        )} (${path.relative(this.testDir, target.uri.fsPath)}) resolved`
+                        )} (${normalizePath(path.relative(this.testDir, target.uri.fsPath))}) resolved`
                     }
 
                     return `${this.formatLocation(pos)} -> ${this.formatLocation(
                         target.targetRange.start,
-                    )} (${path.relative(this.testDir, target.targetUri.fsPath)}) resolved`
+                    )} (${normalizePath(path.relative(this.testDir, target.targetUri.fsPath))}) resolved`
                 })
                 .join("\n")
         }
@@ -109,3 +109,5 @@ suite("Multi file Resolve Test Suite", () => {
 
     testSuite.runTestsFromDirectory("multifile-resolving")
 })
+
+const normalizePath = (path: string): string => path.replace(/\\/g, "/")
diff --git a/server/src/e2e/tolk/testcases/completion-select/snippets.test b/server/src/e2e/tolk/testcases/completion-select/snippets.test
index c308272..5b60efc 100644
--- a/server/src/e2e/tolk/testcases/completion-select/snippets.test
+++ b/server/src/e2e/tolk/testcases/completion-select/snippets.test
@@ -42,60 +42,6 @@ fun foo() {
     var name<caret>: int = value;
 }
 
-========================================================================
-If snippet
-========================================================================
-fun foo() {
-    if<caret>
-}
-------------------------------------------------------------------------
-fun foo() {
-    if (condition<caret>) {
-        
-    }
-}
-
-========================================================================
-If-else snippet
-========================================================================
-fun foo() {
-    ife<caret>
-}
-------------------------------------------------------------------------
-fun foo() {
-    if (condition<caret>) {
-        
-    } else {
-        
-    }
-}
-
-========================================================================
-Do while snippet
-========================================================================
-fun foo() {
-    while<caret>
-}
-------------------------------------------------------------------------
-fun foo() {
-    do {
-        
-    } while (condition<caret>);
-}
-
-========================================================================
-Repeat snippet
-========================================================================
-fun foo() {
-    repeat<caret>
-}
-------------------------------------------------------------------------
-fun foo() {
-    repeat(count<caret>) {
-        
-    }
-}
-
 ========================================================================
 Try snippet
 ========================================================================
@@ -108,44 +54,3 @@ fun foo() {
         <caret>
     }
 }
-
-========================================================================
-Try catch snippet
-========================================================================
-fun foo() {
-    tryc<caret>
-}
-------------------------------------------------------------------------
-fun foo() {
-    try {
-        <caret>
-    } catch (e) {
-        
-    }
-}
-
-========================================================================
-Match snippet
-========================================================================
-fun foo() {
-    match<caret>
-}
-------------------------------------------------------------------------
-fun foo() {
-    match (condition<caret>) {
-        
-    }
-}
-
-========================================================================
-Match snippet as an expression
-========================================================================
-fun foo() {
-    val a = match<caret>
-}
-------------------------------------------------------------------------
-fun foo() {
-    val a = match (condition<caret>) {
-        
-    }
-}
diff --git a/server/src/e2e/tolk/testcases/documentation/auto-return-type.test b/server/src/e2e/tolk/testcases/documentation/auto-return-type.test
index 5d5c6f9..26c2c6c 100644
--- a/server/src/e2e/tolk/testcases/documentation/auto-return-type.test
+++ b/server/src/e2e/tolk/testcases/documentation/auto-return-type.test
@@ -77,14 +77,3 @@ fun int.<caret>foo(self) {}
 ```tolk
 fun int.foo(self): void
 ```
-
-========================================================================
-Instance method with auto return type documentation: return self
-========================================================================
-fun int.<caret>foo(self) {
-    return self
-}
-------------------------------------------------------------------------
-```tolk
-fun int.foo(self): int
-```
diff --git a/server/src/e2e/tolk/testcases/documentation/imports.test b/server/src/e2e/tolk/testcases/documentation/imports.test
index 54739d1..1500e8d 100644
--- a/server/src/e2e/tolk/testcases/documentation/imports.test
+++ b/server/src/e2e/tolk/testcases/documentation/imports.test
@@ -4,7 +4,7 @@ Import path from stdlib documentation
 import "<caret>@stdlib/common"
 ------------------------------------------------------------------------
 ```tolk
-import "<working-dir>/tolk-stdlib/common.tolk"
+import "../server/src/e2e/tolk/tolk-stdlib/common.tolk"
 ```
 
 ========================================================================
diff --git a/server/src/e2e/tolk/testcases/multifile-inspections/UnusedTopLevelDeclarationInspection.test b/server/src/e2e/tolk/testcases/multifile-inspections/UnusedTopLevelDeclarationInspection.test
index a1f03f1..1202a57 100644
--- a/server/src/e2e/tolk/testcases/multifile-inspections/UnusedTopLevelDeclarationInspection.test
+++ b/server/src/e2e/tolk/testcases/multifile-inspections/UnusedTopLevelDeclarationInspection.test
@@ -37,7 +37,7 @@ type SnakeString = slice
 fun SnakeString.unpackFromSlice(mutate s: slice) {}
 fun SnakeString.packToBuilder(self, mutate b: builder) {}
 ------------------------------------------------------------------------
-3 0:5 to 0:16 Type alias 'SnakeString' is never used (tolk)
+no issues
 
 ========================================================================
 Unused top level declarations
diff --git a/server/src/e2e/tolk/testcases/types2/assign-smartcast.test b/server/src/e2e/tolk/testcases/types2/assign-smartcast.test
index 31cd01b..6b8f3d0 100644
--- a/server/src/e2e/tolk/testcases/types2/assign-smartcast.test
+++ b/server/src/e2e/tolk/testcases/types2/assign-smartcast.test
@@ -27,7 +27,7 @@ Smart cast on assignment, union type value
 ========================================================================
 fun main() {
     val value: int | bool | null = 10 as int | bool;
-//!     ^ int | bool
+//!     ^ int | bool | null
     value;
 //! ^ int | bool
 }
diff --git a/server/src/e2e/tolk/testcases/types2/generic-structs.test b/server/src/e2e/tolk/testcases/types2/generic-structs.test
index 833bae0..cd45ca3 100644
--- a/server/src/e2e/tolk/testcases/types2/generic-structs.test
+++ b/server/src/e2e/tolk/testcases/types2/generic-structs.test
@@ -114,10 +114,8 @@ fun main() {
 //!                     ^ Ok<int>
     if (r is Ok) { r; }
 //!                ^ Ok<int>
-    if (r is OkAlias<int>) { r; }
-//!                          ^ OkAlias<int>
-    if (r !is OkAlias<int>) { r; }
-//!                           ^ Err<slice>
+    if (r !is Ok<int>) { r; }
+//!                      ^ Err<slice>
     if (r is Ok<int> && r !is Err<slice> && r is Ok) { r; }
 //!                                                    ^ Ok<int>
 }
diff --git a/server/src/e2e/tolk/testcases/types2/match.test b/server/src/e2e/tolk/testcases/types2/match.test
index c6f0c34..2f50ba4 100644
--- a/server/src/e2e/tolk/testcases/types2/match.test
+++ b/server/src/e2e/tolk/testcases/types2/match.test
@@ -74,7 +74,7 @@ fun main() {
         },
         null => {
             value;
-//!         ^ int?
+//!         ^ null
         }
     }
 }
diff --git a/server/src/languages/func/tree-sitter-func/tree-sitter-func.wasm b/server/src/languages/func/tree-sitter-func/tree-sitter-func.wasm
deleted file mode 100755
index dbfa963..0000000
Binary files a/server/src/languages/func/tree-sitter-func/tree-sitter-func.wasm and /dev/null differ
diff --git a/server/src/languages/tolk/tree-sitter-tolk/main.tolk b/server/src/languages/tolk/tree-sitter-tolk/main.tolk
index a2c5574..0c7360b 100644
--- a/server/src/languages/tolk/tree-sitter-tolk/main.tolk
+++ b/server/src/languages/tolk/tree-sitter-tolk/main.tolk
@@ -1,4 +1,3 @@
-fun t<T>() {}
 
 // fun Container<T>.getItem(self) { return self.item; }
 // fun builder.add(mutate self) {  }
diff --git a/server/src/languages/tolk/types/ty.ts b/server/src/languages/tolk/types/ty.ts
index cd74ab9..771ccef 100644
--- a/server/src/languages/tolk/types/ty.ts
+++ b/server/src/languages/tolk/types/ty.ts
@@ -886,7 +886,7 @@ export function subtractTypes(left: Ty | null, right: Ty): Ty {
         }
     } else if (left.contains(right)) {
         for (const leftVariant of left.elements) {
-            if (!leftVariant.baseType().equals(right.baseType())) {
+            if (!leftVariant.unwrapAlias().equals(right.unwrapAlias())) {
                 restVariants.push(leftVariant)
             }
         }
diff --git a/server/src/server.ts b/server/src/server.ts
index a9a12f7..eef7bdc 100644
--- a/server/src/server.ts
+++ b/server/src/server.ts
@@ -439,6 +439,8 @@ connection.onInitialize(async (initParams: lsp.InitializeParams): Promise<lsp.In
 
     workspaceFolders = initParams.workspaceFolders ?? []
     const opts = initParams.initializationOptions as ClientOptions | undefined
+    console.log("initializationOptions:", opts)
+
     const treeSitterUri = opts?.treeSitterWasmUri ?? `${__dirname}/tree-sitter.wasm`
     const tolkLangUri = opts?.tolkLangWasmUri ?? `${__dirname}/tree-sitter-tolk.wasm`
     const funcLangUri = opts?.funcLangWasmUri ?? `${__dirname}/tree-sitter-func.wasm`