Add convenience initializers to VariableDecl

Sources/SwiftSyntaxBuilder/BooleanLiteralExprConvenienceInitializers.swift

@@ -10,8 +10,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-import SwiftSyntax
-
 extension BooleanLiteralExpr {
   public init(_ value: Bool) {
     self.init(booleanLiteral: value ? .true : .false)

Sources/SwiftSyntaxBuilder/FloatLiteralExprConvenienceInitializers.swift

@@ -10,8 +10,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-import SwiftSyntax
-
 extension FloatLiteralExpr {
   public init(_ value: Float) {
     self.init(floatingDigits: String(value))

Sources/SwiftSyntaxBuilder/IdentifierPatternConvenienceInitializers.swift

@@ -0,0 +1,23 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2021 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+extension IdentifierPattern {
+    init(_ identifier: String) {
+        self.init(identifier: .identifier(identifier))
+    }
+}
+
+extension IdentifierPattern: ExpressibleByStringLiteral {
+  public init(stringLiteral value: String) {
+    self.init(value)
+  }
+}

Sources/SwiftSyntaxBuilder/TypeBuildables.swift → Sources/SwiftSyntaxBuilder/SimpleTypeIdentifierConvenienceInitializers.swift

@@ -18,3 +18,9 @@ extension SimpleTypeIdentifier {
               genericArgumentClause: nil)
   }
 }
+
+extension SimpleTypeIdentifier: ExpressibleByStringLiteral {
+  public init(stringLiteral value: String) {
+    self.init(value)
+  }
+}

Sources/SwiftSyntaxBuilder/TypeAnnotationConvenienceInitializers.swift

@@ -0,0 +1,23 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2021 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+extension TypeAnnotation {
+  public init(_ type: String) {
+    self.init(type: SimpleTypeIdentifier(type))
+  }
+}
+
+extension TypeAnnotation: ExpressibleByStringLiteral {
+  public init(stringLiteral value: String) {
+    self.init(value)
+  }
+}

Sources/SwiftSyntaxBuilder/VariableDeclConvenienceInitializers.swift

@@ -0,0 +1,22 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2021 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import SwiftSyntax
+
+extension VariableDecl {
+    public init(_ letOrVarKeyword: TokenSyntax, name: String, type: String) {
+        self.init(letOrVarKeyword: letOrVarKeyword, bindingsBuilder:  {
+            PatternBinding(pattern: IdentifierPattern(name),
+                           typeAnnotation: TypeAnnotation(type))
+        })
+    }
+}

Tests/SwiftSyntaxBuilderTest/VariableTests.swift

@@ -40,4 +40,21 @@ final class VariableTests: XCTestCase {
     ␣var number: Int = 123
     """)
   }
+
+  func testConvenienceInitializer() {
+    let leadingTrivia = Trivia.garbageText("␣")
+
+    let testCases: [UInt: (TokenSyntax, String, String, String)] = [
+      #line: (TokenSyntax.let, "foo", "Int", "␣let foo: Int"),
+      #line: (TokenSyntax.var, "bar", "Baz", "␣var bar: Baz")
+    ]
+
+    for (line, testCase) in testCases {
+      let (keyword, name, type, expected) = testCase
+      let builder = VariableDecl(keyword, name: name, type: type)
+      let syntax = builder.buildSyntax(format: Format(), leadingTrivia: leadingTrivia)
+
+      XCTAssertEqual(syntax.description, expected, line: line)
+    }
+  }
 }