☂️ New analyzer plugin system

[srawlins]

Tasks needed to deliver a new analyzer plugin system:

• [x] Document requirements. Public doc available
• [ ] Design overall system. Public doc available
• [ ] Design plugin API.
• [ ] Prototype system, to measure memory and CPU.
• [ ] Design workflow for slow plugins.
• [ ] Design workflow for plugin crash.
• [ ] Design for AOT compilation.
• [ ] https://github.com/dart-lang/site-www/issues/5892

[matanlurey]

This is really exciting Sam! If you could use any help trying out prototypes I'd volunteer some time!

[parlough]

@srawlins Would you mind creating go links for your design docs on https://github.com/flutter/website/blob/main/firebase.json? Then you can add them to the top of your docs making them a bit easier to share and discuss publicly.

Community members often follow new go links on flutter.dev as well.

[srawlins]

I'm not good about referencing this issue in my CLs, as all the work is sort of just preparation and grooming the code. So I'll write down some of the under-the-hood changes I've been making. They are largely to support two areas: lint rule APIs and correction producer (mostly quick fix) APIs:

lint rule APIs:

• LinterContext:
  • Deprecate resolveNameInScope (replaced with resolveNameInScope2) (334082) and inTestDir (replaced with extension getter) (365300).
  • Remove analysisOptions, declaredVariables, canBeConst, canBeConstConstructor, inTestDir (replaced with extension getters) (365521).
• LinterContextImpl: remove strictCasts field (344200).
• Mark LintDriver and DartLinter as "only used for linter tools and tests" (334645).
• Remove CamelCaseString and SourceLinter (334645).
• Mark DartLinter.lintPubspecSource as @visibleForTesting (334645).
• LinterOptions: mark enabledLints and analysisOptions final, and remove resourceProvider (334645).
• Move analyzer's top-level function lintFiles, classes ErrorWatchingSink and FileGlobFilter to linter's tool/ directory (334645).
• NodeLintRegistry: remove deprecated addOnClause (366404).
• Remove NodeLintRuleWithContext (366504), Linter, getVisitor, linterVersion (366840), LinterAnalysis.linterUnit, LinterContextUnit2 (366405).
• Simplify LibraryAnalyzer._computeLints (366222).
• Add LinterContextUnit.errorReporter (366405).

correction producer APIs:

• _AbstractCorrectionProducer:
  • Remove strictCasts (344220), invalidNodes, displayStringForType, mightBeImplicitConstructor, nameOfType, shouldWrapParenthesisBeforeAnd (367363).
• CorrectionProducer:
  • Remove getLinterContext (364964).
  • Convert each of assistArguments, fixArguments, multiFixArguments to be List<String>? (364420).
  • Remove errorMessage (367363).
  • Make configure abstract (367363).
• MultiCorrectionProducer: remove typeProvider, typeSystem (367363).
• ResolvedCorrectionProducer: remove coreTypeBool (367363).
• CorrectionUtils:
  • Remove patternOfBoolCondition (347781).
  • Remove findPossibleLocalVariableConflicts (358641).
  • Remove getTypeSource, targetClassElement, and targetExecutableElement (358663).
  • Remove prepareNewStatementLocation (360080).
  • Move prepareNewFieldLocation and prepareNewGetterLocation to DartFileEditBuilder, as addFieldInsertion and addGetterInsertion (360302).
  • Move addMethodInsert and addCaseClauseAtEndInsert to DartEditBuilder (360980).
  • Remove getDefaultValueCode (361132).
  • Move last constructor APIs to DartFileEditBuilder (362063).
  • Remove prepareNewClassMemberLocation (362303).
  • Remove addLibraryImports (363402).
  • Remove indentLeft, indentRight (363404).
  • Remove selectionIncludesNonWhitespaceOutsideNode (363501).
• DartFileEditBuilder:
  • Add addConstructorInsertion, a replacement for both CorrectionUtils.prepareEnumNewConstructorLocation and CorrectionUtils.prepareNewConstructorLocation (361624).
  • Rename add___Insertion APIs to insert___ (362001).
  • Add insertIntoUnitMember (362183).
  • Add a parameter to writeOverride called setSelection which controls whether selection should be set (362183).
• CorrectionProducerContext:
  • Make private: selectionOffset, selectionLength, utils, sessionHelper, unitResult, applyingBulkFixes, diagnostic, node, token (364420).
  • Remove selectionEnd, unit, file, session, workspace, typeProvider; these can be accessed via getters (364420).
• Make private AssistProcessor.generators, multiGenerators, .assistContext, .assists (364420).
• FixProcessor:
  • Make private: FixProcessor.fixContext (364420).
• Remove hasFix top-level function(345347), classes TransformOverride (347641), ExpressionCasePattern (347781), CorrectionUtils_InsertDesc (347780), CancelCorrectionException (348083), Baseprocessor (364360).
• Separate FixProcessor and built-in fix producer mappings into two files (345561).
• Combine DartFixContext and DartFixContextImpl and change constructor to use all named parameters (358382).
• Remove static class Flutter. Most methods are refactored as extension methods. Some unused ones are deleted. Some are inlined into their call sites (362300).
• Remove unused class TransformOverrideSet (340280).
• Use an enum to express how widely a CorrectionProducer can be applied (366740).

I'll update this comment as I make more preparatory changes.