Make CodeBlockItemSyntax expressible by string

(cherry picked from commit e182ac6)

Author: StevenWong12

CodeGeneration/Sources/SyntaxSupport/CommonNodes.swift

@@ -26,6 +26,7 @@ public let COMMON_NODES: [Node] = [
     nameForDiagnostics: nil,
     description: "A CodeBlockItem is any Syntax node that appears on its own line inside a CodeBlock.",
     kind: "Syntax",
+    parserFunction: "parseNonOptionalCodeBlockItem",
     children: [
       Child(
         name: "Item",

CodeGeneration/Sources/generate-swiftsyntax/templates/swiftparser/ParserEntryFile.swift

@@ -100,5 +100,22 @@ let parserEntryFile = SourceFileSyntax(leadingTrivia: copyrightHeader) {
       }
       """
     )
+
+    DeclSyntax(
+      """
+      mutating func parseNonOptionalCodeBlockItem() -> RawCodeBlockItemSyntax {
+        guard let node = self.parseCodeBlockItem(isAtTopLevel: false, allowInitDecl: true) else {
+          // The missing item is not neccessary to be a declaration,
+          // which is just a placeholder here
+          return RawCodeBlockItemSyntax(
+            item: .decl(RawDeclSyntax(RawMissingDeclSyntax(attributes: nil, modifiers: nil, arena: self.arena))),
+            semicolon: nil,
+            arena: self.arena
+          )
+        }
+        return node
+      }
+      """
+    )
   }
 }

Sources/SwiftParser/generated/Parser+Entry.swift

@@ -73,6 +73,14 @@ extension ClosureParameterSyntax: SyntaxParseable {
   }
 }
 
+extension CodeBlockItemSyntax: SyntaxParseable {
+  public static func parse(from parser: inout Parser) -> Self {
+    let node = parser.parseNonOptionalCodeBlockItem()
+    let raw = RawSyntax(parser.parseRemainder(into: node))
+    return Syntax(raw: raw).cast(Self.self)
+  }
+}
+
 extension DeclSyntax: SyntaxParseable {
   public static func parse(from parser: inout Parser) -> Self {
     let node = parser.parseDeclaration()
@@ -184,4 +192,17 @@ fileprivate extension Parser {
     let withUnexpected = layout.replacingChild(at: layout.children.count - 1, with: unexpected.raw, arena: self.arena)
     return R.init(withUnexpected)!
   }
+  
+  mutating func parseNonOptionalCodeBlockItem() -> RawCodeBlockItemSyntax {
+    guard let node = self.parseCodeBlockItem(isAtTopLevel: false, allowInitDecl: true) else {
+      // The missing item is not neccessary to be a declaration,
+      // which is just a placeholder here
+      return RawCodeBlockItemSyntax(
+        item: .decl(RawDeclSyntax(RawMissingDeclSyntax(attributes: nil, modifiers: nil, arena: self.arena))),
+        semicolon: nil,
+        arena: self.arena
+      )
+    }
+    return node
+  }
 }

Sources/SwiftSyntaxBuilder/generated/SyntaxExpressibleByStringInterpolationConformances.swift

@@ -34,6 +34,8 @@ extension CatchClauseSyntax: SyntaxExpressibleByStringInterpolation {}
 
 extension ClosureParameterSyntax: SyntaxExpressibleByStringInterpolation {}
 
+extension CodeBlockItemSyntax: SyntaxExpressibleByStringInterpolation {}
+
 extension DeclSyntax: SyntaxExpressibleByStringInterpolation {}
 
 extension EnumCaseParameterSyntax: SyntaxExpressibleByStringInterpolation {}

Tests/SwiftSyntaxBuilderTest/CollectionNodeFlatteningTests.swift

@@ -44,4 +44,19 @@ final class CollectionNodeFlatteningTests: XCTestCase {
       """
     )
   }
+
+  func test_FlattenCodeBlockItemListWithCodeBlockItemStrings() {
+    let buildable = CodeBlockItemListSyntax {
+      "let one = object.methodOne()"
+      "let two = object.methodTwo()"
+    }
+
+    assertBuildResult(
+      buildable,
+      """
+      let one = object.methodOne()
+      let two = object.methodTwo()
+      """
+    )
+  }
 }

Tests/SwiftSyntaxBuilderTest/StringInterpolationTests.swift

@@ -408,6 +408,26 @@ final class StringInterpolationTests: XCTestCase {
     )
   }
 
+  func testCodeBlockItemInterpolation() {
+    let codeBlockItem: CodeBlockItemSyntax =
+      """
+      func foo() {
+        return bar
+      }
+      """
+
+    XCTAssertTrue(codeBlockItem.is(CodeBlockItemSyntax.self))
+    assertStringsEqualWithDiff(
+      codeBlockItem.description,
+      """
+      func foo() {
+        return bar
+      }
+      """
+    )
+
+  }
+
   func testInvalidTrivia() {
     let invalid = Trivia("/*comment*/ invalid /*comm*/")
     XCTAssertEqual(invalid, [.blockComment("/*comment*/"), .spaces(1), .unexpectedText("invalid"), .spaces(1), .blockComment("/*comm*/")])
@@ -460,4 +480,21 @@ final class StringInterpolationTests: XCTestCase {
       )
     }
   }
+
+  func testInvalidSyntax3() {
+    let invalid: CodeBlockItemSyntax = " "
+
+    XCTAssert(invalid.hasError)
+    XCTAssertThrowsError(try CodeBlockItemSyntax(validating: " ")) { error in
+      assertStringsEqualWithDiff(
+        String(describing: error),
+        """
+
+        1 │ 
+          │ ╰─ error: expected declaration
+
+        """
+      )
+    }
+  }
 }