Added some code improvements from a working branch: (#8822)

* Added some code improvements from a working branch:
* Created a shortened "fileId" for each source file. This reduces memory used for tracking symbols and TypeVars that are scoped to files.
* Removed some unused or redundant code.
* Added assertNever calls to catch potential bugs.
* Renamed a few symbols for consistency and readability.
* Improved handling of literal type expressions that are lazily parsed.
* Refactored literal type printing into a utility module.

* Fixed style issue.

packages/pyright-internal/src/analyzer/analyzerFileInfo.ts

@@ -52,6 +52,7 @@ export interface AnalyzerFileInfo {
     lines: TextRangeCollection<TextRange>;
     typingSymbolAliases: Map<string, string>;
     definedConstants: Map<string, boolean | string>;
+    fileId: string;
     fileUri: Uri;
     moduleName: string;
     isStubFile: boolean;

packages/pyright-internal/src/analyzer/constraintSolution.ts

@@ -16,16 +16,8 @@ export class ConstraintSolutionSet {
     // Indexed by TypeVar ID.
     private _typeVarMap: Map<string, Type | undefined>;
 
-    // See the comment in constraintTracker for details about identifying
-    // solution sets by scope ID.
-    private _scopeIds: Set<string> | undefined;
-
-    constructor(scopeIds?: Set<string>) {
+    constructor() {
         this._typeVarMap = new Map<string, Type>();
-
-        if (scopeIds) {
-            this._scopeIds = new Set<string>(scopeIds);
-        }
     }
 
     isEmpty() {

packages/pyright-internal/src/analyzer/constraintSolver.ts

@@ -236,7 +236,7 @@ export function solveConstraintSet(
     constraintSet: ConstraintSet,
     options?: SolveConstraintsOptions
 ): ConstraintSolutionSet {
-    const solutionSet = new ConstraintSolutionSet(constraintSet.getScopeIds());
+    const solutionSet = new ConstraintSolutionSet();
 
     constraintSet.doForEachTypeVar((entry) => {
         solveTypeVarRecursive(evaluator, constraintSet, options, solutionSet, entry);

packages/pyright-internal/src/analyzer/constraintTracker.ts

@@ -38,6 +38,7 @@ export interface TypeVarConstraints {
 // Records the constraints information for a set of type variables
 // associated with a callee's signature.
 export class ConstraintSet {
+    // Maps type variable IDs to their current constraints.
     private _typeVarMap: Map<string, TypeVarConstraints>;
 
     // A set of one or more TypeVar scope IDs that identify this constraint set.

packages/pyright-internal/src/analyzer/declarationUtils.ts

@@ -7,6 +7,7 @@
  * Collection of static methods that operate on declarations.
  */
 
+import { assertNever } from '../common/debug';
 import { getEmptyRange } from '../common/textRange';
 import { Uri } from '../common/uri/uri';
 import { NameNode, ParseNodeType } from '../parser/parseNodes';
@@ -138,6 +139,10 @@ export function getNameFromDeclaration(declaration: Declaration) {
                 declaration.node.d.valueExpr.nodeType === ParseNodeType.Name
                 ? declaration.node.d.valueExpr.d.value
                 : undefined;
+
+        default: {
+            assertNever(declaration);
+        }
     }
 
     throw new Error(`Shouldn't reach here`);
@@ -167,6 +172,10 @@ export function getNameNodeForDeclaration(declaration: Declaration): NameNode |
         case DeclarationType.Intrinsic:
         case DeclarationType.SpecialBuiltInClass:
             return undefined;
+
+        default: {
+            assertNever(declaration);
+        }
     }
 
     throw new Error(`Shouldn't reach here`);
@@ -197,7 +206,7 @@ export function getDeclarationsWithUsesLocalNameRemoved(decls: Declaration[]) {
     });
 }
 
-export function createSynthesizedAliasDeclaration(uri: Uri): AliasDeclaration {
+export function synthesizeAliasDeclaration(uri: Uri): AliasDeclaration {
     // The only time this decl is used is for IDE services such as
     // the find all references, hover provider and etc.
     return {

packages/pyright-internal/src/analyzer/parseTreeUtils.ts

@@ -2876,7 +2876,7 @@ export function getScopeIdForNode(node: ParseNode): string {
     }
 
     const fileInfo = AnalyzerNodeInfo.getFileInfo(node);
-    return `${fileInfo.fileUri.key}.${node.start.toString()}-${name}`;
+    return `${fileInfo.fileId}.${node.start.toString()}-${name}`;
 }
 
 // Walks up the parse tree and finds all scopes that can provide

packages/pyright-internal/src/analyzer/parseTreeWalker.ts

@@ -795,23 +795,23 @@ export class ParseTreeVisitor<T> {
         return this._default;
     }
 
-    visitPatternMappingExpandEntry(node: PatternMappingExpandEntryNode) {
+    visitPatternMapping(node: PatternMappingNode) {
         return this._default;
     }
 
-    visitPatternSequence(node: PatternSequenceNode) {
+    visitPatternMappingExpandEntry(node: PatternMappingExpandEntryNode) {
         return this._default;
     }
 
-    visitPatternValue(node: PatternValueNode) {
+    visitPatternMappingKeyEntry(node: PatternMappingKeyEntryNode) {
         return this._default;
     }
 
-    visitPatternMappingKeyEntry(node: PatternMappingKeyEntryNode) {
+    visitPatternSequence(node: PatternSequenceNode) {
         return this._default;
     }
 
-    visitPatternMapping(node: PatternMappingNode) {
+    visitPatternValue(node: PatternValueNode) {
         return this._default;
     }
 

packages/pyright-internal/src/analyzer/sourceFile.ts

@@ -71,6 +71,9 @@ export enum IPythonMode {
     CellDocs,
 }
 
+// A monotonically increasing number used to create unique file IDs.
+let nextUniqueFileId = 1;
+
 class WriteableData {
     // Number that is incremented every time the diagnostics
     // are updated.
@@ -193,6 +196,10 @@ export class SourceFile {
     // a real file on disk.
     private readonly _uri: Uri;
 
+    // A short string that is guaranteed to uniquely
+    // identify this file.
+    private readonly _fileId: string;
+
     // Period-delimited import path for the module.
     private _moduleName: string;
 
@@ -258,6 +265,7 @@ export class SourceFile {
 
         this._editMode = editMode;
         this._uri = uri;
+        this._fileId = this._makeFileId(uri);
         this._moduleName = moduleName;
         this._isStubFile = uri.hasExtension('.pyi');
         this._isThirdPartyImport = isThirdPartyImport;
@@ -954,6 +962,27 @@ export class SourceFile {
         return new TextRangeDiagnosticSink(lines);
     }
 
+    // Creates a short string that can be used to uniquely identify
+    // this file from all other files. It is used in the type evaluator
+    // to distinguish between types that are defined in different files
+    // or scopes.
+    private _makeFileId(uri: Uri) {
+        const maxNameLength = 8;
+
+        // Use a small portion of the file name to help with debugging.
+        let fileName = uri.fileNameWithoutExtensions;
+        if (fileName.length > maxNameLength) {
+            fileName = fileName.substring(fileName.length - maxNameLength);
+        }
+
+        // Append a number to guarantee uniqueness.
+        const uniqueNumber = nextUniqueFileId++;
+
+        // Use a "/" to separate the two components, since this
+        // character will never appear in a file name.
+        return `${fileName}/${uniqueNumber.toString()}`;
+    }
+
     // Computes an updated set of accumulated diagnostics for the file
     // based on the partial diagnostics from various analysis stages.
     private _recomputeDiagnostics(configOptions: ConfigOptions) {
@@ -1302,6 +1331,7 @@ export class SourceFile {
             lines: this._writableData.tokenizerLines!,
             typingSymbolAliases: this._writableData.parserOutput!.typingSymbolAliases,
             definedConstants: configOptions.defineConstant,
+            fileId: this._fileId,
             fileUri: this._uri,
             moduleName: this.getModuleName(),
             isStubFile: this._isStubFile,

packages/pyright-internal/src/analyzer/typeEvaluator.ts

@@ -85,7 +85,7 @@ import {
     YieldFromNode,
     YieldNode,
 } from '../parser/parseNodes';
-import { ParseOptions, ParseTextMode, Parser } from '../parser/parser';
+import { ParseOptions, Parser, ParseTextMode } from '../parser/parser';
 import { KeywordType, OperatorType, StringTokenFlags } from '../parser/tokenizerTypes';
 import { AnalyzerFileInfo, ImportLookup, isAnnotationEvaluationPostponed } from './analyzerFileInfo';
 import * as AnalyzerNodeInfo from './analyzerNodeInfo';
@@ -120,11 +120,11 @@ import {
     VariableDeclaration,
 } from './declaration';
 import {
-    createSynthesizedAliasDeclaration,
     getDeclarationsWithUsesLocalNameRemoved,
     getNameNodeForDeclaration,
     resolveAliasDeclaration as resolveAliasDeclarationUtil,
     ResolvedAliasInfo,
+    synthesizeAliasDeclaration,
 } from './declarationUtils';
 import {
     addOverloadsToFunctionType,
@@ -21070,7 +21070,7 @@ export function createTypeEvaluator(
                     // Synthesize an alias declaration for this name part. The only
                     // time this case is used is for IDE services such as
                     // the find all references, hover provider and etc.
-                    declarations.push(createSynthesizedAliasDeclaration(importInfo.resolvedUris[namePartIndex]));
+                    declarations.push(synthesizeAliasDeclaration(importInfo.resolvedUris[namePartIndex]));
                 }
             }
         } else if (node.parent && node.parent.nodeType === ParseNodeType.Argument && node === node.parent.d.name) {
@@ -23052,15 +23052,6 @@ export function createTypeEvaluator(
             prevSrcType = curSrcType;
         }
 
-        // If we're enforcing invariance, literal types must match as well.
-        if ((flags & AssignTypeFlags.Invariant) !== 0) {
-            const srcIsLiteral = srcType.priv.literalValue !== undefined;
-            const destIsLiteral = destType.priv.literalValue !== undefined;
-            if (srcIsLiteral !== destIsLiteral) {
-                return false;
-            }
-        }
-
         // Handle tuple, which supports a variable number of type arguments.
         if (destType.priv.tupleTypeArgs && curSrcType.priv.tupleTypeArgs) {
             return assignTupleTypeArgs(
@@ -26958,11 +26949,16 @@ export function createTypeEvaluator(
         );
 
         if (parseResults.parseTree) {
+            const fileInfo = AnalyzerNodeInfo.getFileInfo(node);
             parseResults.diagnostics.forEach((diag) => {
-                addDiagnosticWithSuppressionCheck('error', diag.message, node);
+                fileInfo.diagnosticSink.addDiagnosticWithTextRange('error', diag.message, node);
             });
 
             parseResults.parseTree.parent = node;
+
+            // Add the new subtree to the parse tree so it can participate in
+            // language server operations like find and replace.
+            node.d.annotation = parseResults.parseTree;
             return parseResults.parseTree;
         }
 

packages/pyright-internal/src/analyzer/typePrinter.ts

@@ -12,6 +12,7 @@ import { assert } from '../common/debug';
 import { ParamCategory } from '../parser/parseNodes';
 import { isTypedKwargs } from './parameterUtils';
 import * as ParseTreeUtils from './parseTreeUtils';
+import { printBytesLiteral, printStringLiteral } from './typePrinterUtils';
 import {
     ClassType,
     EnumLiteral,
@@ -39,9 +40,6 @@ import {
 } from './types';
 import { convertToInstance, doForEachSubtype, isNoneInstance, isTupleClass, removeNoneFromUnion } from './typeUtils';
 
-const singleTickRegEx = /'/g;
-const escapedDoubleQuoteRegEx = /\\"/g;
-
 export const enum PrintTypeFlags {
     None = 0,
 
@@ -161,37 +159,9 @@ export function printLiteralValue(type: ClassType, quotation = "'"): string {
         }
 
         if (type.shared.name === 'bytes') {
-            let bytesString = '';
-
-            // There's no good built-in conversion routine in javascript to convert
-            // bytes strings. Determine on a character-by-character basis whether
-            // it can be rendered into an ASCII character. If not, use an escape.
-            for (let i = 0; i < effectiveLiteralValue.length; i++) {
-                const char = effectiveLiteralValue.substring(i, i + 1);
-                const charCode = char.charCodeAt(0);
-
-                if (charCode >= 20 && charCode <= 126) {
-                    if (charCode === 34) {
-                        bytesString += '\\' + char;
-                    } else {
-                        bytesString += char;
-                    }
-                } else {
-                    bytesString += `\\x${((charCode >> 4) & 0xf).toString(16)}${(charCode & 0xf).toString(16)}`;
-                }
-            }
-
-            literalStr = `b"${bytesString}"`;
+            literalStr = printBytesLiteral(effectiveLiteralValue);
         } else {
-            // JSON.stringify will perform proper escaping for " case.
-            // So, we only need to do our own escaping for ' case.
-            literalStr = JSON.stringify(effectiveLiteralValue).toString();
-            if (quotation !== '"') {
-                literalStr = `'${literalStr
-                    .substring(1, literalStr.length - 1)
-                    .replace(escapedDoubleQuoteRegEx, '"')
-                    .replace(singleTickRegEx, "\\'")}'`; // CodeQL [SM02383] Code ql is just wrong here. We don't need to replace backslashes.
-            }
+            literalStr = printStringLiteral(effectiveLiteralValue, quotation);
         }
     } else if (typeof literalValue === 'boolean') {
         literalStr = literalValue ? 'True' : 'False';
@@ -523,7 +493,7 @@ function printTypeInternal(
             case TypeCategory.Union: {
                 // If this is a value expression that evaluates to a union type but is
                 // not a type alias, simply print the special form ("UnionType").
-                if (TypeBase.isInstantiable(type) && type.props?.specialForm && !aliasInfo) {
+                if (TypeBase.isInstantiable(type) && type.props?.specialForm && !type.props?.typeAliasInfo) {
                     return printTypeInternal(
                         type.props.specialForm,
                         printTypeFlags,

packages/pyright-internal/src/analyzer/typePrinterUtils.ts

@@ -0,0 +1,49 @@
+/*
+ * typePrinterUtils.ts
+ * Copyright (c) Microsoft Corporation.
+ * Licensed under the MIT license.
+ * Author: Eric Traut
+ *
+ * Simple utility functions used by the type printer.
+ */
+
+export function printStringLiteral(value: string, quotation = '"'): string {
+    const singleTickRegEx = /'/g;
+    const escapedDoubleQuoteRegEx = /\\"/g;
+
+    // JSON.stringify will perform proper escaping for " case.
+    // So, we only need to do our own escaping for ' case.
+    let literalStr = JSON.stringify(value).toString();
+    if (quotation !== '"') {
+        literalStr = `'${literalStr
+            .substring(1, literalStr.length - 1)
+            .replace(escapedDoubleQuoteRegEx, '"')
+            .replace(singleTickRegEx, "\\'")}'`; // CodeQL [SM02383] Code ql is just wrong here. We don't need to replace backslashes.
+    }
+
+    return literalStr;
+}
+
+export function printBytesLiteral(value: string) {
+    let bytesString = '';
+
+    // There's no good built-in conversion routine in javascript to convert
+    // bytes strings. Determine on a character-by-character basis whether
+    // it can be rendered into an ASCII character. If not, use an escape.
+    for (let i = 0; i < value.length; i++) {
+        const char = value.substring(i, i + 1);
+        const charCode = char.charCodeAt(0);
+
+        if (charCode >= 20 && charCode <= 126) {
+            if (charCode === 34) {
+                bytesString += '\\' + char;
+            } else {
+                bytesString += char;
+            }
+        } else {
+            bytesString += `\\x${((charCode >> 4) & 0xf).toString(16)}${(charCode & 0xf).toString(16)}`;
+        }
+    }
+
+    return `b"${bytesString}"`;
+}

packages/pyright-internal/src/languageService/documentSymbolCollector.ts

@@ -14,8 +14,8 @@ import * as AnalyzerNodeInfo from '../analyzer/analyzerNodeInfo';
 import { AliasDeclaration, Declaration, DeclarationType, isAliasDeclaration } from '../analyzer/declaration';
 import {
     areDeclarationsSame,
-    createSynthesizedAliasDeclaration,
     getDeclarationsWithUsesLocalNameRemoved,
+    synthesizeAliasDeclaration,
 } from '../analyzer/declarationUtils';
 import { getModuleNode, getStringNodeValueRange } from '../analyzer/parseTreeUtils';
 import { ParseTreeWalker } from '../analyzer/parseTreeWalker';
@@ -450,7 +450,7 @@ function _getDeclarationsForNonModuleNameNode(
         const type = evaluator.getType(node);
         if (type?.category === TypeCategory.Module) {
             // Synthesize decl for the module.
-            return [createSynthesizedAliasDeclaration(type.priv.fileUri)];
+            return [synthesizeAliasDeclaration(type.priv.fileUri)];
         }
     }