[SR-5744] Refactoring action to convert if-let to guard-let and vice versa

include/swift/IDE/RefactoringKinds.def

@@ -66,6 +66,10 @@ RANGE_REFACTORING(ExpandTernaryExpr, "Expand Ternary Expression", expand.ternary
 
 RANGE_REFACTORING(ConvertToTernaryExpr, "Convert To Ternary Expression", convert.ternary.expr)
 
+RANGE_REFACTORING(ConvertIfLetExprToGuardExpr, "Convert To Guard Expression", convert.iflet.to.guard.expr)
+
+RANGE_REFACTORING(ConvertGuardExprToIfLetExpr, "Convert To IfLet Expression", convert.to.iflet.expr)
+
 // These internal refactorings are designed to be helpful for working on
 // the compiler/standard library, etc., but are likely to be just confusing and
 // noise for general development.

lib/IDE/Refactoring.cpp

@@ -2068,6 +2068,180 @@ bool RefactoringActionExpandTernaryExpr::performChange() {
   return false; //don't abort
 }
 
+bool RefactoringActionConvertIfLetExprToGuardExpr::
+  isApplicable(ResolvedRangeInfo Info, DiagnosticEngine &Diag) {
+
+  if (Info.Kind != RangeKind::SingleStatement
+      && Info.Kind != RangeKind::MultiStatement)
+    return false;
+
+  if (Info.ContainedNodes.empty())
+    return false;
+
+  IfStmt *If = nullptr;
+
+  if (Info.ContainedNodes.size() == 1) {
+    if (auto S = Info.ContainedNodes[0].dyn_cast<Stmt*>()) {
+      If = dyn_cast<IfStmt>(S);
+    }
+  }
+
+  if (!If)
+    return false;
+
+  auto CondList = If->getCond();
+
+  if (CondList.size() == 1) {
+    auto E = CondList[0];
+    auto P = E.getKind();
+    if (P == swift::StmtConditionElement::CK_PatternBinding) {
+      auto Body = dyn_cast_or_null<BraceStmt>(If->getThenStmt());
+      if (Body)
+        return true;
+    }
+  }
+
+  return false;
+}
+
+bool RefactoringActionConvertIfLetExprToGuardExpr::performChange() {
+
+  auto S = RangeInfo.ContainedNodes[0].dyn_cast<Stmt*>();
+  IfStmt *If = dyn_cast<IfStmt>(S);
+  auto CondList = If->getCond();
+
+  // Get if-let condition
+  SourceRange range = CondList[0].getSourceRange();
+  SourceManager &SM = RangeInfo.RangeContext->getASTContext().SourceMgr;
+  auto CondCharRange = Lexer::getCharSourceRangeFromSourceRange(SM, range);
+
+  auto Body = dyn_cast_or_null<BraceStmt>(If->getThenStmt());
+
+  // Get if-let then body.
+  auto firstElement = Body->getElements()[0];
+  auto lastElement = Body->getElements().back();
+  SourceRange bodyRange = firstElement.getSourceRange();
+  bodyRange.widen(lastElement.getSourceRange());
+  auto BodyCharRange = Lexer::getCharSourceRangeFromSourceRange(SM, bodyRange);
+
+  llvm::SmallString<64> DeclBuffer;
+  llvm::raw_svector_ostream OS(DeclBuffer);
+
+  llvm::StringRef Space = " ";
+  llvm::StringRef NewLine = "\n";
+
+  OS << tok::kw_guard << Space;
+  OS << CondCharRange.str().str() << Space;
+  OS << tok::kw_else << Space;
+  OS << tok::l_brace << NewLine;
+
+  // Get if-let else body.
+  if (auto *ElseBody = dyn_cast_or_null<BraceStmt>(If->getElseStmt())) {
+    auto firstElseElement = ElseBody->getElements()[0];
+    auto lastElseElement = ElseBody->getElements().back();
+    SourceRange elseBodyRange = firstElseElement.getSourceRange();
+    elseBodyRange.widen(lastElseElement.getSourceRange());
+    auto ElseBodyCharRange = Lexer::getCharSourceRangeFromSourceRange(SM, elseBodyRange);
+    OS << ElseBodyCharRange.str().str() << NewLine;
+  }
+
+  OS << tok::kw_return << NewLine;
+  OS << tok::r_brace << NewLine;
+  OS << BodyCharRange.str().str();
+
+  // Replace if-let to guard
+  auto ReplaceRange = RangeInfo.ContentRange;
+  EditConsumer.accept(SM, ReplaceRange, DeclBuffer.str());
+
+  return false;
+}
+
+bool RefactoringActionConvertGuardExprToIfLetExpr::
+  isApplicable(ResolvedRangeInfo Info, DiagnosticEngine &Diag) {
+  if (Info.Kind != RangeKind::SingleStatement
+      && Info.Kind != RangeKind::MultiStatement)
+    return false;
+
+  if (Info.ContainedNodes.empty())
+    return false;
+
+  GuardStmt *guardStmt = nullptr;
+
+  if (Info.ContainedNodes.size() > 0) {
+    if (auto S = Info.ContainedNodes[0].dyn_cast<Stmt*>()) {
+      guardStmt = dyn_cast<GuardStmt>(S);
+    }
+  }
+
+  if (!guardStmt)
+    return false;
+
+  auto CondList = guardStmt->getCond();
+
+  if (CondList.size() == 1) {
+    auto E = CondList[0];
+    auto P = E.getPatternOrNull();
+    if (P && E.getKind() == swift::StmtConditionElement::CK_PatternBinding)
+      return true;
+  }
+
+  return false;
+}
+
+bool RefactoringActionConvertGuardExprToIfLetExpr::performChange() {
+
+  // Get guard stmt
+  auto S = RangeInfo.ContainedNodes[0].dyn_cast<Stmt*>();
+  GuardStmt *Guard = dyn_cast<GuardStmt>(S);
+
+  // Get guard condition
+  auto CondList = Guard->getCond();
+
+  // Get guard condition source
+  SourceRange range = CondList[0].getSourceRange();
+  SourceManager &SM = RangeInfo.RangeContext->getASTContext().SourceMgr;
+  auto CondCharRange = Lexer::getCharSourceRangeFromSourceRange(SM, range);
+
+  llvm::SmallString<64> DeclBuffer;
+  llvm::raw_svector_ostream OS(DeclBuffer);
+
+  llvm::StringRef Space = " ";
+  llvm::StringRef NewLine = "\n";
+
+  OS << tok::kw_if << Space;
+  OS << CondCharRange.str().str() << Space;
+  OS << tok::l_brace << NewLine;
+
+  // Get nodes after guard to place them at if-let body
+  if (RangeInfo.ContainedNodes.size() > 1) {
+    auto S = RangeInfo.ContainedNodes[1].getSourceRange();
+    S.widen(RangeInfo.ContainedNodes.back().getSourceRange());
+    auto BodyCharRange = Lexer::getCharSourceRangeFromSourceRange(SM, S);
+    OS << BodyCharRange.str().str() << NewLine;
+  }
+  OS << tok::r_brace;
+
+  // Get guard body
+  auto Body = dyn_cast_or_null<BraceStmt>(Guard->getBody());
+
+  if (Body && Body->getElements().size() > 1) {
+    auto firstElement = Body->getElements()[0];
+    auto lastElement = Body->getElements().back();
+    SourceRange bodyRange = firstElement.getSourceRange();
+    bodyRange.widen(lastElement.getSourceRange());
+    auto BodyCharRange = Lexer::getCharSourceRangeFromSourceRange(SM, bodyRange);
+    OS << Space << tok::kw_else << Space << tok::l_brace << NewLine;
+    OS << BodyCharRange.str().str() << NewLine;
+    OS << tok::r_brace;
+  }
+
+  // Replace guard to if-let
+  auto ReplaceRange = RangeInfo.ContentRange;
+  EditConsumer.accept(SM, ReplaceRange, DeclBuffer.str());
+
+  return false;
+}
+
 /// Struct containing info about an IfStmt that can be converted into an IfExpr.
 struct ConvertToTernaryExprInfo {
   ConvertToTernaryExprInfo() {}

test/refactoring/ConvertToGuard/Outputs/basic/L15-3.swift.expected

@@ -0,0 +1,34 @@
+func foo(idxOpt: Int?) {
+  if let idx = idxOpt {
+    print(idx)
+  }
+}
+
+func bar(fooOpt: Int?) {
+  if let foo = fooOpt {
+    let incrementedFoo = foo + 1
+    print(incrementedFoo)
+  }
+}
+
+func fooBar(fooOpt: Int?) {
+  guard let foo = fooOpt else {
+return
+}
+let incrementedFoo = foo + 1
+    print(incrementedFoo)
+    print(foo)
+}
+
+func barFoo(idxOpt: Int?) {
+  if let idx = idxOpt {
+    print(idx)
+  } else {
+    print("nil")
+  }
+}
+
+
+
+
+

test/refactoring/ConvertToGuard/Outputs/basic/L2-3.swift.expected

@@ -0,0 +1,34 @@
+func foo(idxOpt: Int?) {
+  guard let idx = idxOpt else {
+return
+}
+print(idx)
+}
+
+func bar(fooOpt: Int?) {
+  if let foo = fooOpt {
+    let incrementedFoo = foo + 1
+    print(incrementedFoo)
+  }
+}
+
+func fooBar(fooOpt: Int?) {
+  if let foo = fooOpt {
+    let incrementedFoo = foo + 1
+    print(incrementedFoo)
+    print(foo)
+  }
+}
+
+func barFoo(idxOpt: Int?) {
+  if let idx = idxOpt {
+    print(idx)
+  } else {
+    print("nil")
+  }
+}
+
+
+
+
+

test/refactoring/ConvertToGuard/Outputs/basic/L23-3.swift.expected

@@ -0,0 +1,33 @@
+func foo(idxOpt: Int?) {
+  if let idx = idxOpt {
+    print(idx)
+  }
+}
+
+func bar(fooOpt: Int?) {
+  if let foo = fooOpt {
+    let incrementedFoo = foo + 1
+    print(incrementedFoo)
+  }
+}
+
+func fooBar(fooOpt: Int?) {
+  if let foo = fooOpt {
+    let incrementedFoo = foo + 1
+    print(incrementedFoo)
+    print(foo)
+  }
+}
+
+func barFoo(idxOpt: Int?) {
+  guard let idx = idxOpt else {
+print("nil")
+return
+}
+print(idx)
+}
+
+
+
+
+

test/refactoring/ConvertToGuard/Outputs/basic/L8-3.swift.expected

@@ -0,0 +1,34 @@
+func foo(idxOpt: Int?) {
+  if let idx = idxOpt {
+    print(idx)
+  }
+}
+
+func bar(fooOpt: Int?) {
+  guard let foo = fooOpt else {
+return
+}
+let incrementedFoo = foo + 1
+    print(incrementedFoo)
+}
+
+func fooBar(fooOpt: Int?) {
+  if let foo = fooOpt {
+    let incrementedFoo = foo + 1
+    print(incrementedFoo)
+    print(foo)
+  }
+}
+
+func barFoo(idxOpt: Int?) {
+  if let idx = idxOpt {
+    print(idx)
+  } else {
+    print("nil")
+  }
+}
+
+
+
+
+

test/refactoring/ConvertToGuard/basic.swift

@@ -0,0 +1,42 @@
+func foo(idxOpt: Int?) {
+  if let idx = idxOpt {
+    print(idx)
+  }
+}
+
+func bar(fooOpt: Int?) {
+  if let foo = fooOpt {
+    let incrementedFoo = foo + 1
+    print(incrementedFoo)
+  }
+}
+
+func fooBar(fooOpt: Int?) {
+  if let foo = fooOpt {
+    let incrementedFoo = foo + 1
+    print(incrementedFoo)
+    print(foo)
+  }
+}
+
+func barFoo(idxOpt: Int?) {
+  if let idx = idxOpt {
+    print(idx)
+  } else {
+    print("nil")
+  }
+}
+
+// RUN: rm -rf %t.result && mkdir -p %t.result
+
+// RUN: %refactor -convert-to-guard -source-filename %s -pos=2:3 -end-pos=4:4 > %t.result/L2-3.swift
+// RUN: diff -u %S/Outputs/basic/L2-3.swift.expected %t.result/L2-3.swift
+
+// RUN: %refactor -convert-to-guard -source-filename %s -pos=8:3 -end-pos=11:4 > %t.result/L8-3.swift
+// RUN: diff -u %S/Outputs/basic/L8-3.swift.expected %t.result/L8-3.swift
+
+// RUN: %refactor -convert-to-guard -source-filename %s -pos=15:3 -end-pos=19:4 > %t.result/L15-3.swift
+// RUN: diff -u %S/Outputs/basic/L15-3.swift.expected %t.result/L15-3.swift
+
+// RUN: %refactor -convert-to-guard -source-filename %s -pos=23:3 -end-pos=27:4 > %t.result/L23-3.swift
+// RUN: diff -u %S/Outputs/basic/L23-3.swift.expected %t.result/L23-3.swift