Replace "sidecar" references with "documentation extension" in tests

Updates comments, local variable names, and one test method name to use
the canonical "documentation extension" terminology already used
throughout Sources/

rdar://67827882

Author: franklinsch

Tests/SwiftDocCTests/Infrastructure/AutomaticCurationTests.swift

@@ -149,7 +149,7 @@ class AutomaticCurationTests: XCTestCase {
             return section.identifiers.contains("doc://org.swift.docc.example/documentation/SideKit/SideClass/Element")
         }).isEmpty)
 
-        // Verify that element `SideKit/SideClass/path` curated in sidecar under `SideKit`
+        // Verify that element `SideKit/SideClass/path` curated in a documentation extension under `SideKit`
         // is NOT automatically curated in `SideClass`'s "Topics"
         XCTAssertTrue(renderNode.topicSections.filter({ section -> Bool in
             return section.identifiers.contains("doc://org.swift.docc.example/documentation/SideKit/SideClass/path")
@@ -285,7 +285,7 @@ class AutomaticCurationTests: XCTestCase {
                     graph.relationships.append(newRelationship)
                 }
 
-                // Add a sidecar file for this symbol
+                // Add a documentation extension file for this symbol
                 try """
                 # ``SideKit/SideClass\(suffix)``
                 

Tests/SwiftDocCTests/Infrastructure/DocumentationContext/DocumentationContextTests.swift

@@ -924,7 +924,7 @@ class DocumentationContextTests: XCTestCase {
         XCTAssertTrue(parent.path.hasSuffix("MyKit/MyClass"))
 
         //
-        // Test sidecar documentation
+        // Test documentation extension
         //
 
         // MyProtocol is loaded
@@ -2176,7 +2176,7 @@ let expected = """
         XCTAssertNoThrow(try context.entity(with: ResolvedTopicReference(bundleID: "org.swift.docc.example", path: "/documentation/SideKit/sideClass-swift.var", sourceLanguage: .swift)))
     }
 
-    func testUnresolvedSidecarDiagnostics() async throws {
+    func testUnresolvedDocumentationExtensionDiagnostics() async throws {
         let catalog = Folder(name: "unit-test.docc", content: [
             JSONFile(name: "ModuleName.symbols.json", content: makeSymbolGraph(
                 moduleName: "ModuleName",
@@ -2203,15 +2203,14 @@ let expected = """
         let unmatchedDocExtensionDiagnostic = try XCTUnwrap(context.diagnostics.first(where: { $0.identifier == "org.swift.docc.SymbolUnmatched" }))
         XCTAssertNotNil(unmatchedDocExtensionDiagnostic)
 
-        // Verify the diagnostics have the sidecar source URL
+        // Verify the diagnostics have the documentation extension source URL
         let source = try XCTUnwrap(unmatchedDocExtensionDiagnostic.source)
-        
-        let unmatchedSidecarDiagnostic = unmatchedDocExtensionDiagnostic
+
         XCTAssertTrue(bundle.markupURLs.contains(source.standardizedFileURL), "One of the files should be the diagnostic source")
-        XCTAssertEqual(unmatchedSidecarDiagnostic.range, SourceLocation(line: 1, column: 3, source: unmatchedDocExtensionDiagnostic.source)..<SourceLocation(line: 1, column: 32, source: unmatchedDocExtensionDiagnostic.source))
-        
-        XCTAssertEqual(unmatchedSidecarDiagnostic.summary, "No symbol matched '/ModuleName/UnknownSymbol'. 'UnknownSymbol' doesn't exist at '/ModuleName'.")
-        XCTAssertEqual(unmatchedSidecarDiagnostic.severity, .warning)
+        XCTAssertEqual(unmatchedDocExtensionDiagnostic.range, SourceLocation(line: 1, column: 3, source: unmatchedDocExtensionDiagnostic.source)..<SourceLocation(line: 1, column: 32, source: unmatchedDocExtensionDiagnostic.source))
+
+        XCTAssertEqual(unmatchedDocExtensionDiagnostic.summary, "No symbol matched '/ModuleName/UnknownSymbol'. 'UnknownSymbol' doesn't exist at '/ModuleName'.")
+        XCTAssertEqual(unmatchedDocExtensionDiagnostic.severity, .warning)
     }
 
     func testExtendingSymbolWithSpaceInName() async throws {

Tests/SwiftDocCTests/Infrastructure/DocumentationCuratorTests.swift

@@ -425,7 +425,7 @@ class DocumentationCuratorTests: XCTestCase {
 
     func testGroupLinkValidation() async throws {
         let (_, _, context) = try await testBundleAndContext(copying: "LegacyBundle_DoNotUseInNewTests", excludingPaths: []) { root in
-            // Create a sidecar with invalid group links
+            // Create a documentation extension with invalid group links
             try! """
             # ``SideKit``
             ## Topics
@@ -470,7 +470,7 @@ class DocumentationCuratorTests: XCTestCase {
         try crawler.crawlChildren(of: reference, prepareForCuration: {_ in }) { (_, _) in }
 
         // Verify the crawler emitted warnings for the 3 invalid links in the sidekit Topics/See Alsos groups
-        // in both the sidecar and the api collection article
+        // in both the documentation extension and the api collection article
         XCTAssertEqual(crawler.diagnostics.filter({ $0.identifier == "org.swift.docc.UnexpectedTaskGroupItem" }).count, 6)
         XCTAssertTrue(crawler.diagnostics
             .filter({ $0.identifier == "org.swift.docc.UnexpectedTaskGroupItem" })

Tests/SwiftDocCTests/Model/SemaToRenderNodeTests.swift

@@ -944,12 +944,12 @@ class SemaToRenderNodeTests: XCTestCase {
 
         let node = try context.entity(with: ResolvedTopicReference(bundleID: bundle.id, path: "/documentation/MyKit/MyProtocol", sourceLanguage: .swift))
 
-        // Verify that `MyProtocol` the symbol is loaded in the topic graph, but the `MyProtocol` sidecar article was removed.
+        // Verify that `MyProtocol` the symbol is loaded in the topic graph, but the `MyProtocol` documentation extension was removed.
         let matches = context.knownPages.filter({ reference -> Bool in
             return reference.path.contains("MyProtocol")
         })
 
-        // Verify the sidecar article was merged successfully into the symbol
+        // Verify the documentation extension was merged successfully into the symbol
         XCTAssertEqual(matches.count, 1)
         guard matches.count == 1 else { return }
 

Tests/SwiftDocCTests/Rendering/RenderNodeTranslatorTests.swift

@@ -147,12 +147,12 @@ class RenderNodeTranslatorTests: XCTestCase {
 
     func testAutomaticOverviewAndDiscussionHeadings() async throws {
         guard let myFunctionDiscussion = try await findDiscussion(forSymbolPath: "/documentation/MyKit/MyClass/myFunction()", configureBundle: { url in
-            let sidecarURL = url.appendingPathComponent("/documentation/myFunction.md")
+            let documentationExtensionURL = url.appendingPathComponent("/documentation/myFunction.md")
             try """
             # ``MyKit/MyClass/myFunction()``
             
             This is the overview for myFunction.
-            """.write(to: sidecarURL, atomically: true, encoding: .utf8)
+            """.write(to: documentationExtensionURL, atomically: true, encoding: .utf8)
         }) else {
             return
         }
@@ -166,15 +166,15 @@ class RenderNodeTranslatorTests: XCTestCase {
         )
 
         guard let myClassDiscussion = try await findDiscussion(forSymbolPath: "/documentation/MyKit/MyClass", configureBundle: { url in
-            let sidecarURL = url.appendingPathComponent("/documentation/myclass.md")
-            XCTAssert(FileManager.default.fileExists(atPath: sidecarURL.path), "Make sure that this overrides the existing file.")
+            let documentationExtensionURL = url.appendingPathComponent("/documentation/myclass.md")
+            XCTAssert(FileManager.default.fileExists(atPath: documentationExtensionURL.path), "Make sure that this overrides the existing file.")
             try """
             # ``MyKit/MyClass``
 
             This is the abstract (because MyClass doesn't have an in-source abstract).
 
             This is the overview for MyClass.
-            """.write(to: sidecarURL, atomically: true, encoding: .utf8)
+            """.write(to: documentationExtensionURL, atomically: true, encoding: .utf8)
         }) else {
             return
         }