refactor baseline code into a class, move some duplicated logic from …

…both the language server and cli to the class and fix some bugs with the automatic baseline updating

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

@@ -48,7 +48,7 @@ import { SourceMapper } from './sourceMapper';
 import { SymbolTable } from './symbol';
 import { TestWalker } from './testWalker';
 import { TypeEvaluator } from './typeEvaluatorTypes';
-import { sortDiagnosticsAndMatchBaseline } from '../baseline';
+import { BaselineHandler } from '../baseline';
 
 // Limit the number of import cycles tracked per source file.
 const _maxImportCyclesPerFile = 4;
@@ -1247,7 +1247,10 @@ export class SourceFile {
         // Now add in the "unnecessary type ignore" diagnostics.
         diagList = diagList.concat(unnecessaryTypeIgnoreDiags);
 
-        diagList = sortDiagnosticsAndMatchBaseline(this.fileSystem, configOptions.projectRoot, this._uri, diagList);
+        diagList = new BaselineHandler(this.fileSystem, configOptions.projectRoot).sortDiagnosticsAndMatchBaseline(
+            this._uri,
+            diagList
+        );
 
         // If we're not returning any diagnostics, filter out all of
         // the errors and warnings, leaving only the unreachable code