From dd8d05551a510dd962db89aec84c4d1ab8f09716 Mon Sep 17 00:00:00 2001
From: detachhead <detachhead@users.noreply.github.com>
Date: Wed, 4 Sep 2024 20:20:06 +1000
Subject: [PATCH] fix incorrect semantic highlighting of `Never`

---
 .../src/analyzer/semanticTokensWalker.ts       |  8 +++-----
 .../src/tests/semanticTokensProvider.test.ts   | 18 +++++++++---------
 2 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/packages/pyright-internal/src/analyzer/semanticTokensWalker.ts b/packages/pyright-internal/src/analyzer/semanticTokensWalker.ts
index eea3ed8f3d..631a0733b1 100644
--- a/packages/pyright-internal/src/analyzer/semanticTokensWalker.ts
+++ b/packages/pyright-internal/src/analyzer/semanticTokensWalker.ts
@@ -1,6 +1,6 @@
 import { ParseTreeWalker } from './parseTreeWalker';
 import { TypeEvaluator } from './typeEvaluatorTypes';
-import { ClassType, FunctionType, OverloadedType, Type, TypeCategory, TypeFlags } from './types';
+import { ClassType, FunctionType, getTypeAliasInfo, OverloadedType, Type, TypeCategory, TypeFlags } from './types';
 import {
     ClassNode,
     DecoratorNode,
@@ -218,10 +218,8 @@ export class SemanticTokensWalker extends ParseTreeWalker {
                 // to differentiate between "instances" of `Never` and type aliases/annotations of Never.
                 // this is probably extremely cringe since i have no idea what this is doing and i literally
                 // just brute forced random shit until all the tests passed
-                (typeResult.type.category !== TypeCategory.Never &&
-                    typeResult.type.category !== TypeCategory.Unbound &&
-                    typeResult.type.flags & TypeFlags.Instantiable) ||
-                (typeResult.type.category === TypeCategory.Unbound && !typeResult.includesIllegalTypeAliasDecl)
+                (typeResult.type.category === TypeCategory.Never && !typeResult.includesVariableDecl) ||
+                (getTypeAliasInfo(type) && !typeResult.includesIllegalTypeAliasDecl)
             ) {
                 this._addItem(node.start, node.length, SemanticTokenTypes.type, []);
                 return;
diff --git a/packages/pyright-internal/src/tests/semanticTokensProvider.test.ts b/packages/pyright-internal/src/tests/semanticTokensProvider.test.ts
index 82351d2e2a..1ca5b228cf 100644
--- a/packages/pyright-internal/src/tests/semanticTokensProvider.test.ts
+++ b/packages/pyright-internal/src/tests/semanticTokensProvider.test.ts
@@ -22,8 +22,8 @@ if (process.platform !== 'win32' || !process.env['CI']) {
         expect(result).toStrictEqual([
             //TODO: fix duplicates
             { type: 'namespace', modifiers: [], start: 5, length: 6 },
-            { type: 'class', modifiers: [], start: 19, length: 5 },
-            { type: 'class', modifiers: [], start: 19, length: 5 },
+            { type: 'type', modifiers: [], start: 19, length: 5 },
+            { type: 'type', modifiers: [], start: 19, length: 5 },
             { type: 'class', modifiers: [], start: 26, length: 8 },
             { type: 'class', modifiers: [], start: 38, length: 3 },
             { type: 'namespace', modifiers: [], start: 47, length: 11 },
@@ -52,12 +52,12 @@ if (process.platform !== 'win32' || !process.env['CI']) {
         const result = semanticTokenizeSampleFile('never.py');
         expect(result).toStrictEqual([
             { type: 'namespace', modifiers: [], start: 5, length: 6 }, // typing
-            { type: 'class', modifiers: [], start: 19, length: 5 }, // Never
-            { type: 'class', modifiers: [], start: 19, length: 5 }, // Never
+            { type: 'type', modifiers: [], start: 19, length: 5 }, // Never
+            { type: 'type', modifiers: [], start: 19, length: 5 }, // Never
             { type: 'variable', modifiers: [], start: 26, length: 3 }, // foo
             { type: 'type', modifiers: [], start: 31, length: 5 }, // Never
-            { type: 'class', modifiers: [], start: 37, length: 3 }, // bar
-            { type: 'class', modifiers: [], start: 43, length: 5 }, // Never
+            { type: 'type', modifiers: [], start: 37, length: 3 }, // bar
+            { type: 'type', modifiers: [], start: 43, length: 5 }, // Never
             { type: 'function', modifiers: ['definition'], start: 54, length: 3 }, // baz
             { type: 'function', modifiers: [], start: 54, length: 3 }, // baz
             { type: 'type', modifiers: [], start: 63, length: 5 }, // Never
@@ -69,10 +69,10 @@ if (process.platform !== 'win32' || !process.env['CI']) {
             { type: 'type', modifiers: [], start: 112, length: 5 }, // Never
             { type: 'parameter', modifiers: [], start: 120, length: 3 }, // foo
             { type: 'variable', modifiers: [], start: 128, length: 5 }, // value
-            { type: 'class', modifiers: [], start: 135, length: 4 }, // Type
-            { type: 'class', modifiers: [], start: 142, length: 5 }, // Never
+            { type: 'type', modifiers: [], start: 135, length: 4 }, // Type
+            { type: 'type', modifiers: [], start: 142, length: 5 }, // Never
             { type: 'variable', modifiers: [], start: 148, length: 5 }, // value
-            { type: 'variable', modifiers: [], start: 155, length: 4 }, // Type (should be type. https://github.com/DetachHead/basedpyright/issues/490)
+            { type: 'type', modifiers: [], start: 155, length: 4 }, // Type
             { type: 'function', modifiers: ['definition'], start: 169, length: 8 }, // inferred
             { type: 'function', modifiers: [], start: 169, length: 8 }, // inferred
             { type: 'variable', modifiers: [], start: 185, length: 5 }, // value