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[analysis_server] Split DartUnitHoverComputer.compute() into smaller …
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…methods

No functional changes here, I'm just trying to simplify the hover implementation a little as this method had gotten quite long and deeply nested. We've discussed improving hover support for patterns and keywords and hopefully this'll make that easier.

Change-Id: I974f7fb0fbb99a967b5970f99b36ef3601df4ea3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/318701
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>
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@DanTup
DanTup authored and Commit Queue committed Aug 7, 2023
1 parent 0e32c36 commit 2a811a0
Showing 1 changed file with 179 additions and 136 deletions.
315 changes: 179 additions & 136 deletions pkg/analysis_server/lib/src/computer/computer_hover.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,10 @@ import 'package:analyzer/src/dart/ast/utilities.dart';
import 'package:analyzer/src/dartdoc/dartdoc_directive_info.dart';
import 'package:path/path.dart' as path;

/// Information about a library to display in a hover.
typedef _LibraryInfo = ({String? libraryName, String? libraryPath})?;
typedef _OffsetLength = ({int offset, int length});

/// A computer for the hover at the specified offset of a Dart
/// [CompilationUnit].
class DartUnitHoverComputer {
Expand All @@ -37,177 +41,216 @@ class DartUnitHoverComputer {
return null;
}

SyntacticEntity? locationEntity;
if (node is NamedCompilationUnitMember) {
locationEntity = node.name;
} else if (node is Expression) {
locationEntity = node;
} else if (node is ExtensionDeclaration) {
locationEntity = node.name;
} else if (node is FormalParameter) {
locationEntity = node.name;
} else if (node is MethodDeclaration) {
locationEntity = node.name;
} else if (node is NamedType) {
locationEntity = node.name2;
} else if (node is ConstructorDeclaration) {
locationEntity = node.name ?? node.returnType;
} else if (node is DeclaredIdentifier) {
locationEntity = node.name;
} else if (node is VariableDeclaration) {
locationEntity = node.name;
} else if (node is VariablePattern) {
locationEntity = node.name;
} else if (node is PatternFieldName) {
locationEntity = node.name;
} else if (node is WildcardPattern) {
locationEntity = node.name;
}
if (locationEntity == null) {
var locationEntity = _locationEntity(node);
node = _targetNode(node);
if (node == null || locationEntity == null) {
return null;
}

var parent = node.parent;
var grandParent = parent?.parent;
if (parent is NamedType &&
grandParent is ConstructorName &&
grandParent.parent is InstanceCreationExpression) {
node = grandParent.parent;
} else if (parent is ConstructorName &&
grandParent is InstanceCreationExpression) {
node = grandParent;
} else if (node is SimpleIdentifier &&
parent is ConstructorDeclaration &&
parent.name != null) {
node = parent;
}
if (node != null &&
(node is CompilationUnitMember ||
node is Expression ||
node is FormalParameter ||
node is MethodDeclaration ||
node is NamedType ||
node is ConstructorDeclaration ||
node is DeclaredIdentifier ||
node is VariableDeclaration ||
node is VariablePattern ||
node is PatternFieldName ||
node is DartPattern)) {
// For constructors, the location should cover the type name and
// constructor name (for both calls and declarations).
HoverInformation hover;
if (node is InstanceCreationExpression) {
hover = HoverInformation(
node.constructorName.offset,
node.constructorName.length,
);
} else if (node is ConstructorDeclaration) {
var offset = node.returnType.offset;
var end = node.name?.end ?? node.returnType.end;
var length = end - node.returnType.offset;
hover = HoverInformation(offset, length);
} else {
hover = HoverInformation(locationEntity.offset, locationEntity.length);
}
if (node is CompilationUnitMember ||
node is Expression ||
node is FormalParameter ||
node is MethodDeclaration ||
node is NamedType ||
node is ConstructorDeclaration ||
node is DeclaredIdentifier ||
node is VariableDeclaration ||
node is VariablePattern ||
node is PatternFieldName ||
node is DartPattern) {
var range = _hoverRange(node, locationEntity);
var hover = HoverInformation(range.offset, range.length);
// element
var element = ElementLocator.locate(node);
if (element != null) {
// variable, if synthetic accessor
if (element is PropertyAccessorElement) {
if (element.isSynthetic) {
element = element.variable;
}
element = element.nonSynthetic;
}
// description
var description = _elementDisplayString(element);
hover.elementDescription = description;
if (description != null &&
node is InstanceCreationExpression &&
node.keyword == null) {
var prefix = node.isConst ? '(const) ' : '(new) ';
hover.elementDescription = prefix + description;
}
hover.elementDescription = _elementDisplayString(node, element);
hover.elementKind = element.kind.displayName;
hover.isDeprecated = element.hasDeprecated;
// not local element
if (element.enclosingElement is! ExecutableElement) {
// containing class
var containingClass =
element.thisOrAncestorOfType<InterfaceElement>();
if (containingClass != null && containingClass != element) {
hover.containingClassDescription = containingClass.displayName;
}
hover.containingClassDescription = _containingClass(element);
// containing library
var library = element.library;
if (library != null) {
var uri = library.source.uri;
var analysisSession = _unit.declaredElement?.session;
if (uri.isScheme('file') && analysisSession != null) {
// for 'file:' URIs, use the path after the project root
var context = analysisSession.resourceProvider.pathContext;
var projectRootDir =
analysisSession.analysisContext.contextRoot.root.path;
var relativePath =
context.relative(context.fromUri(uri), from: projectRootDir);
if (context.style == path.Style.windows) {
var pathList = context.split(relativePath);
hover.containingLibraryName = pathList.join('/');
} else {
hover.containingLibraryName = relativePath;
}
} else {
hover.containingLibraryName = uri.toString();
}
hover.containingLibraryPath = library.source.fullName;
}
var libraryInfo = _libraryInfo(element);
hover.containingLibraryName = libraryInfo?.libraryName;
hover.containingLibraryPath = libraryInfo?.libraryPath;
}
// documentation
hover.dartdoc = computePreferredDocumentation(
_dartdocInfo, element, documentationPreference);
}
// parameter
if (node is Expression) {
hover.parameter = _elementDisplayString(
node.staticParameterElement,
);
}
hover.parameter = _parameterDisplayString(node);
// types
{
var parent = node.parent;
DartType? staticType;
if (node is Expression &&
(element == null || element is VariableElement)) {
staticType = _getTypeOfDeclarationOrReference(node);
} else if (element is VariableElement) {
staticType = element.type;
} else if (parent is MethodInvocation && parent.methodName == node) {
staticType = parent.staticInvokeType;
if (staticType != null && staticType is DynamicType) {
staticType = null;
}
} else if (node is PatternFieldName && parent is PatternField) {
staticType = parent.pattern.matchedValueType;
} else if (node is DartPattern) {
staticType = node.matchedValueType;
}
hover.staticType = _typeDisplayString(staticType);
}
hover.staticType = _typeDisplayString(node, element);
// done
return hover;
}
// not an expression
return null;
}

String? _elementDisplayString(Element? element) {
return element?.getDisplayString(
/// Gets the name of the containing class of [element].
String? _containingClass(Element element) {
var containingClass = element.thisOrAncestorOfType<InterfaceElement>();
return containingClass != null && containingClass != element
? containingClass.displayName
: null;
}

/// Gets the display string for [element].
///
/// This is usually `element.getDisplayString()` but may contain additional
/// information to disambiguate things like constructors from types (and
/// whether they are const).
String? _elementDisplayString(AstNode node, Element? element) {
var displayString = element?.getDisplayString(
withNullability: _unit.isNonNullableByDefault,
multiline: true,
);

if (displayString != null &&
node is InstanceCreationExpression &&
node.keyword == null) {
var prefix = node.isConst ? '(const) ' : '(new) ';
displayString = prefix + displayString;
}

return displayString;
}

String? _typeDisplayString(DartType? type) {
return type?.getDisplayString(
/// Computes the range this hover applies to.
///
/// This is usually the range of [entity] but may be adjusted for entities
/// like constructor names.
_OffsetLength _hoverRange(AstNode node, SyntacticEntity entity) {
// For constructors, the location should cover the type name and
// constructor name (for both calls and declarations).
if (node is InstanceCreationExpression) {
return (
offset: node.constructorName.offset,
length: node.constructorName.length,
);
} else if (node is ConstructorDeclaration) {
var offset = node.returnType.offset;
var end = node.name?.end ?? node.returnType.end;
var length = end - node.returnType.offset;
return (offset: offset, length: length);
} else {
return (offset: entity.offset, length: entity.length);
}
}

/// Returns information about the library that contains [element].
_LibraryInfo _libraryInfo(Element element) {
var library = element.library;
if (library == null) {
return null;
}

var uri = library.source.uri;
var analysisSession = _unit.declaredElement?.session;

String? libraryName, libraryPath;
if (uri.isScheme('file') && analysisSession != null) {
// for 'file:' URIs, use the path after the project root
var context = analysisSession.resourceProvider.pathContext;
var projectRootDir =
analysisSession.analysisContext.contextRoot.root.path;
var relativePath =
context.relative(context.fromUri(uri), from: projectRootDir);
if (context.style == path.Style.windows) {
var pathList = context.split(relativePath);
libraryName = pathList.join('/');
} else {
libraryName = relativePath;
}
} else {
libraryName = uri.toString();
}
libraryPath = library.source.fullName;

return (libraryName: libraryName, libraryPath: libraryPath);
}

/// Returns the [SyntacticEntity] that should be used as the range for this
/// hover.
///
/// Returns `null` if there is no valid entity for this hover.
SyntacticEntity? _locationEntity(AstNode node) {
return switch (node) {
NamedCompilationUnitMember() => node.name,
Expression() => node,
ExtensionDeclaration() => node.name,
FormalParameter() => node.name,
MethodDeclaration() => node.name,
NamedType() => node.name2,
ConstructorDeclaration() => node.name ?? node.returnType,
DeclaredIdentifier() => node.name,
VariableDeclaration() => node.name,
VariablePattern() => node.name,
PatternFieldName() => node.name,
WildcardPattern() => node.name,
_ => null,
};
}

/// Gets the display string for the type of the parameter.
///
/// Returns `null` if the parameter is not an expression.
String? _parameterDisplayString(AstNode node) {
if (node is Expression) {
return _elementDisplayString(
node,
node.staticParameterElement,
);
}
return null;
}

/// Adjusts the target node for constructors.
AstNode? _targetNode(AstNode node) {
var parent = node.parent;
var grandParent = parent?.parent;
if (parent is NamedType &&
grandParent is ConstructorName &&
grandParent.parent is InstanceCreationExpression) {
return grandParent.parent;
} else if (parent is ConstructorName &&
grandParent is InstanceCreationExpression) {
return grandParent;
} else if (node is SimpleIdentifier &&
parent is ConstructorDeclaration &&
parent.name != null) {
return parent;
}
return node;
}

/// Returns information abtout the static type of [node].
String? _typeDisplayString(AstNode node, Element? element) {
var parent = node.parent;
DartType? staticType;
if (node is Expression && (element == null || element is VariableElement)) {
staticType = _getTypeOfDeclarationOrReference(node);
} else if (element is VariableElement) {
staticType = element.type;
} else if (parent is MethodInvocation && parent.methodName == node) {
staticType = parent.staticInvokeType;
if (staticType != null && staticType is DynamicType) {
staticType = null;
}
} else if (node is PatternFieldName && parent is PatternField) {
staticType = parent.pattern.matchedValueType;
} else if (node is DartPattern) {
staticType = node.matchedValueType;
}
return staticType?.getDisplayString(
withNullability: _unit.isNonNullableByDefault);
}

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