Merge pull request #41 from dylansturg/condition_statement_indentation

Indent continuation lines in conditions for if & guard statements.

Sources/SwiftFormatPrettyPrint/TokenStreamCreator.swift

@@ -394,6 +394,16 @@ private final class TokenStreamCreator: SyntaxVisitor {
   func visit(_ node: IfStmtSyntax) -> SyntaxVisitorContinueKind {
     after(node.ifKeyword, tokens: .space)
 
+    // Add break groups around any conditions after the first so that those conditions have at least
+    // 1 non-continuation based indent from an indentation stack. Without that indent, all
+    // continuation lines in the condition are indented by the same amount as the condition's first
+    // line because continuation breaks don't stack. There are no breaks around the first condition
+    // because if-statements look better without a break between the "if" and the first condition.
+    for condition in node.conditions.dropFirst() {
+      before(condition.firstToken, tokens: .break(.open, size: 0))
+      after(condition.lastToken, tokens: .break(.close(mustBreak: false), size: 0))
+    }
+
     arrangeBracesAndContents(of: node.body, contentsKeyPath: \.statements)
 
     let elsePrecedingBreak = config.lineBreakBeforeControlFlowKeywords ? Token.newline : Token.space
@@ -408,7 +418,16 @@ private final class TokenStreamCreator: SyntaxVisitor {
   }
 
   func visit(_ node: GuardStmtSyntax) -> SyntaxVisitorContinueKind {
-    after(node.guardKeyword, tokens: .break)
+    after(node.guardKeyword, tokens: .space)
+
+    // Add break groups around all conditions, similar to the break groups used around if-statement
+    // conditions. For guard-statements, breaking after the "guard" is visually acceptable hence the
+    // first condition is included.
+    for condition in node.conditions {
+      before(condition.firstToken, tokens: .break(.open, size: 0))
+      after(condition.lastToken, tokens: .break(.close(mustBreak: false), size: 0))
+    }
+
     before(node.elseKeyword, tokens: .break(.reset), .open)
     after(node.elseKeyword, tokens: .space)
     before(node.body.leftBrace, tokens: .close)
@@ -1063,7 +1082,7 @@ private final class TokenStreamCreator: SyntaxVisitor {
   func visit(_ node: ConditionElementSyntax) -> SyntaxVisitorContinueKind {
     before(node.firstToken, tokens: .open)
     if let comma = node.trailingComma {
-      after(comma, tokens: .close, .break)
+      after(comma, tokens: .close, .break(.same))
     } else {
       after(node.lastToken, tokens: .close)
     }

Tests/SwiftFormatPrettyPrintTests/GuardStmtTests.swift

@@ -107,4 +107,51 @@ public class GuardStmtTests: PrettyPrintTestCase {
 
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 60)
   }
+
+  public func testContinuationLineBreaking() {
+    let input =
+      """
+      guard let someObject = object as? Int,
+        let anotherCastedObject = object as? SomeOtherSlightlyLongerType else {
+        return nil
+      }
+      guard let someObject = object as? SomeLongLineBreakingType,
+        let anotherCastedObject = object as? SomeOtherSlightlyLongerType else {
+        return nil
+      }
+      guard let someCastedObject = someFunc(foo, bar, baz, quxxe, far, fab, faz),
+        let anotherCastedObject = object as? SomeOtherSlightlyLongerType else {
+        return nil
+      }
+      """
+
+    let expected =
+      """
+      guard let someObject = object as? Int,
+        let anotherCastedObject = object
+          as? SomeOtherSlightlyLongerType
+      else {
+        return nil
+      }
+      guard
+        let someObject = object
+          as? SomeLongLineBreakingType,
+        let anotherCastedObject = object
+          as? SomeOtherSlightlyLongerType
+      else {
+        return nil
+      }
+      guard
+        let someCastedObject = someFunc(
+          foo, bar, baz, quxxe, far, fab, faz),
+        let anotherCastedObject = object
+          as? SomeOtherSlightlyLongerType
+      else {
+        return nil
+      }
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 40)
+  }
 }

Tests/SwiftFormatPrettyPrintTests/IfStmtTests.swift

@@ -216,6 +216,53 @@ public class IfStmtTests: PrettyPrintTestCase {
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 44)
   }
 
+  public func testContinuationLineBreakIndentation() {
+    let input =
+      """
+      if let someObject = object as? Int,
+        let anotherCastedObject = object as? SomeOtherSlightlyLongerType,
+        let thirdObject = object as? Int {
+        return nil
+      }
+      if let someObject = object as? SomeLongLineBreakingType,
+        let anotherCastedObject = object as? SomeOtherSlightlyLongerType {
+        return nil
+      }
+      if let someCastedObject = someFunc(foo, bar, baz, quxxe, far, fab, faz),
+        let anotherCastedObject = object as? SomeOtherSlightlyLongerType {
+        return nil
+      }
+      """
+
+    let expected =
+      """
+      if let someObject = object as? Int,
+        let anotherCastedObject = object
+          as? SomeOtherSlightlyLongerType,
+        let thirdObject = object as? Int
+      {
+        return nil
+      }
+      if let someObject = object
+        as? SomeLongLineBreakingType,
+        let anotherCastedObject = object
+          as? SomeOtherSlightlyLongerType
+      {
+        return nil
+      }
+      if let someCastedObject = someFunc(
+        foo, bar, baz, quxxe, far, fab, faz),
+        let anotherCastedObject = object
+          as? SomeOtherSlightlyLongerType
+      {
+        return nil
+      }
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 50)
+  }
+
   public func testHangingOpenBreakIsTreatedLikeContinuation() {
     let input =
       """

Tests/SwiftFormatPrettyPrintTests/XCTestManifests.swift

@@ -249,6 +249,7 @@ extension GuardStmtTests {
     //   `swift test --generate-linuxmain`
     // to regenerate.
     static let __allTests__GuardStmtTests = [
+        ("testContinuationLineBreaking", testContinuationLineBreaking),
         ("testGuardStatement", testGuardStatement),
         ("testGuardWithFuncCall", testGuardWithFuncCall),
         ("testOpenBraceIsGluedToElseKeyword", testOpenBraceIsGluedToElseKeyword),
@@ -270,6 +271,7 @@ extension IfStmtTests {
     //   `swift test --generate-linuxmain`
     // to regenerate.
     static let __allTests__IfStmtTests = [
+        ("testContinuationLineBreakIndentation", testContinuationLineBreakIndentation),
         ("testHangingOpenBreakIsTreatedLikeContinuation", testHangingOpenBreakIsTreatedLikeContinuation),
         ("testIfElseStatement_breakBeforeElse", testIfElseStatement_breakBeforeElse),
         ("testIfElseStatement_noBreakBeforeElse", testIfElseStatement_noBreakBeforeElse),
@@ -377,6 +379,16 @@ extension RepeatStmtTests {
     ]
 }
 
+extension SemiColonTypeTests {
+    // DO NOT MODIFY: This is autogenerated, use:
+    //   `swift test --generate-linuxmain`
+    // to regenerate.
+    static let __allTests__SemiColonTypeTests = [
+        ("testNoSemicolon", testNoSemicolon),
+        ("testSemicolon", testSemicolon),
+    ]
+}
+
 extension SomeTypeTests {
     // DO NOT MODIFY: This is autogenerated, use:
     //   `swift test --generate-linuxmain`
@@ -567,6 +579,7 @@ public func __allTests() -> [XCTestCaseEntry] {
         testCase(OperatorDeclTests.__allTests__OperatorDeclTests),
         testCase(ProtocolDeclTests.__allTests__ProtocolDeclTests),
         testCase(RepeatStmtTests.__allTests__RepeatStmtTests),
+        testCase(SemiColonTypeTests.__allTests__SemiColonTypeTests),
         testCase(SomeTypeTests.__allTests__SomeTypeTests),
         testCase(StringTests.__allTests__StringTests),
         testCase(StructDeclTests.__allTests__StructDeclTests),