Add literal expression builders

Author: akkyie

Sources/SwiftSyntaxBuilder/Expression/Buildables/IntegerLiteral.swift

@@ -0,0 +1,33 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2019 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
+
+public struct IntegerLiteral: ExprBuildable {
+    let value: Int
+
+    public init(_ value: Int) {
+        self.value = value
+    }
+
+    public func buildExpr(format: Format, leadingTrivia: Trivia) -> ExprSyntax {
+        SyntaxFactory.makeIntegerLiteralExpr(
+            digits: SyntaxFactory.makeIntegerLiteral(String(value))
+        )
+    }
+}
+
+extension IntegerLiteral: ExpressibleByIntegerLiteral {
+    public init(integerLiteral value: Int) {
+        self.init(value)
+    }
+}

Sources/SwiftSyntaxBuilder/Expression/Buildables/StringLiteral.swift

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+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2019 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
+
+public struct StringLiteral: ExprBuildable {
+    let value: String
+
+    public init(_ value: String) {
+        self.value = value
+    }
+
+    public func buildExpr(format: Format, leadingTrivia: Trivia) -> ExprSyntax {
+        SyntaxFactory.makeStringLiteralExpr(value)
+    }
+}
+
+extension StringLiteral: ExpressibleByStringLiteral {
+    public init(stringLiteral value: String) {
+        self.init(value)
+    }
+}

Tests/SwiftSyntaxBuilderTest/Expression/IntegerLiteralTests.swift

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+import XCTest
+import SwiftSyntax
+
+@testable import SwiftSyntaxBuilder
+
+final class IntegerLiteralTests: XCTestCase {
+  let format = Format(indentWidth: 2).indented()
+
+  func testIntegerLiteral() {
+    let testCases: [UInt: (IntegerLiteral, String)] = [
+      #line: (IntegerLiteral(123), "123"),
+      #line: (IntegerLiteral(-123), "-123"),
+      #line: (123, "123"),
+      #line: (-123, "-123"),
+    ]
+
+    for (line, testCase) in testCases {
+      let (builder, expected) = testCase
+      let syntax = builder.buildSyntax(format: format, leadingTrivia: .zero)
+
+      var text = ""
+      syntax.write(to: &text)
+
+      XCTAssertEqual(text, expected, line: line)
+    }
+  }
+}

Tests/SwiftSyntaxBuilderTest/Expression/StringLiteralTests.swift

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+import XCTest
+import SwiftSyntax
+
+@testable import SwiftSyntaxBuilder
+
+final class StringLiteralTests: XCTestCase {
+  let format = Format(indentWidth: 2).indented()
+
+  func testStringLiteral() {
+    let testCases: [UInt: (StringLiteral, String)] = [
+      #line: (StringLiteral(""), "\"\""),
+      #line: (StringLiteral("asdf"), #""asdf""#),
+      #line: ("", "\"\""),
+      #line: ("asdf", #""asdf""#),
+    ]
+
+    for (line, testCase) in testCases {
+      let (builder, expected) = testCase
+      let syntax = builder.buildSyntax(format: format, leadingTrivia: .zero)
+
+      var text = ""
+      syntax.write(to: &text)
+
+      XCTAssertEqual(text, expected, line: line)
+    }
+  }
+}