Extract link resolution code from the documentation context (#306)

* Extract most link resolution code from DocumentationContext

* Stop waiting for request if external resolver client encounters fails

* Remove unnecessary calls to remove temp files in tests.

Also, fix a handful of typos in tests and comments.

* Add missing symbol relationships in test data

* Avoid changing kind of symbol in tests via known disambiguation

* Fix various correctness issues in test symbol graph files

* Fix inconsistent path component in test symbol graph files

* Minor grammar: 'indeterministic' -> 'non-deterministic'

Author: d-ronnqvist

Sources/SwiftDocC/Infrastructure/Symbol Link Resolution/AbsoluteSymbolLink.swift renamed to Sources/SwiftDocC/DocumentationService/Convert/Symbol Link Resolution/AbsoluteSymbolLink.swift

@@ -38,7 +38,7 @@ struct DocumentationCurator {
         }
 
         // Optimization for absolute links.
-        if let cached = context.referenceFor(absoluteSymbolPath: destination, parent: resolved) {
+        if let cached = context.documentationCacheBasedLinkResolver.referenceFor(absoluteSymbolPath: destination, parent: resolved) {
             return cached
         }
 

Sources/SwiftDocC/Infrastructure/Symbol Link Resolution/DocCSymbolRepresentable.swift renamed to Sources/SwiftDocC/DocumentationService/Convert/Symbol Link Resolution/DocCSymbolRepresentable.swift

@@ -68,6 +68,7 @@ class ExternalReferenceResolverServiceClient {
                 }
             } catch {
                 result = .failure(.failedToEncodeRequest(underlyingError: error))
+                resultGroup.leave()
             }
         }
 

Sources/SwiftDocC/Infrastructure/DocumentationContext.swift

@@ -209,7 +209,7 @@ enum GeneratedDocumentationTopics {
     ///   - symbolsURLHierarchy: A symbol graph hierarchy as created during symbol registration.
     ///   - context: A documentation context to update.
     ///   - bundle: The current documentation bundle.
-    static func createInheritedSymbolsAPICollections(relationships: Set<SymbolGraph.Relationship>, symbolsURLHierarchy: inout BidirectionalTree<ResolvedTopicReference>, context: DocumentationContext, bundle: DocumentationBundle) throws {
+    static func createInheritedSymbolsAPICollections(relationships: Set<SymbolGraph.Relationship>, parentOfFunction: (ResolvedTopicReference) -> ResolvedTopicReference?, context: DocumentationContext, bundle: DocumentationBundle) throws {
         var inheritanceIndex = InheritedSymbols()
 
         // Walk the symbol graph relationships and look for parent <-> child links that stem in a different module.
@@ -227,14 +227,14 @@ enum GeneratedDocumentationTopics {
                let extends = child.symbol?.mixins[SymbolGraph.Symbol.Swift.Extension.mixinKey] as? SymbolGraph.Symbol.Swift.Extension {
                 var originParentSymbol: ResolvedTopicReference? = nil
                 if let originSymbol = context.symbolIndex[origin.identifier] {
-                    originParentSymbol = try? symbolsURLHierarchy.parent(of: originSymbol.reference)
+                    originParentSymbol = parentOfFunction(originSymbol.reference)
                 }
                 // Add the inherited symbol to the index.
                 try inheritanceIndex.add(child.reference, to: parent.reference, originDisplayName: origin.displayName, originParentSymbol: originParentSymbol, extendedModuleName: extends.extendedModule)
             }
         }
 
-        // Create the API Collection nodes and the neccessary topic graph curation.
+        // Create the API Collection nodes and the necessary topic graph curation.
         for (typeReference, collections) in inheritanceIndex.implementingTypes where !collections.inheritedFromTypeName.isEmpty {
             for (_, collection) in collections.inheritedFromTypeName where !collection.identifiers.isEmpty {
                 // Create a collection for the given provider type's inherited symbols

Sources/SwiftDocC/Infrastructure/DocumentationCurator.swift

@@ -134,7 +134,7 @@ struct RenderContentCompiler: MarkupVisitor {
     }
 
     func resolveSymbolReference(destination: String) -> ResolvedTopicReference? {
-        if let cached = context.referenceFor(absoluteSymbolPath: destination, parent: identifier) {
+        if let cached = context.documentationCacheBasedLinkResolver.referenceFor(absoluteSymbolPath: destination, parent: identifier) {
             return cached
         } 
 

Sources/SwiftDocC/Infrastructure/External Data/ExternalReferenceResolverServiceClient.swift

@@ -113,7 +113,7 @@ struct MarkupReferenceResolver: MarkupRewriter {
     }
 
     mutating func resolveAbsoluteSymbolLink(unresolvedDestination: String, elementRange range: SourceRange?) -> String {
-        if let cached = context.referenceFor(absoluteSymbolPath: unresolvedDestination, parent: rootReference) {
+        if let cached = context.documentationCacheBasedLinkResolver.referenceFor(absoluteSymbolPath: unresolvedDestination, parent: rootReference) {
             guard context.topicGraph.isLinkable(cached) == true else {
                 problems.append(disabledLinkDestinationProblem(reference: cached, source: source, range: range, severity: .warning))
                 return unresolvedDestination