From 75bae2065b1fbd588251186565e4e750fb84fe24 Mon Sep 17 00:00:00 2001
From: Perryvw <perry.wesel@gmail.com>
Date: Sat, 17 Mar 2018 13:53:20 +0100
Subject: [PATCH] Added do-while loop

---
 src/Transpiler.ts       | 15 +++++++++++++++
 test/src/util.ts        | 14 ++++++++++++++
 test/unit/while.spec.ts | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 62 insertions(+)
 create mode 100644 test/unit/while.spec.ts

diff --git a/src/Transpiler.ts b/src/Transpiler.ts
index 2cfff1e04..ac5cb41ae 100644
--- a/src/Transpiler.ts
+++ b/src/Transpiler.ts
@@ -160,6 +160,8 @@ export class LuaTranspiler {
                 return this.transpileIf(<ts.IfStatement>node);
             case ts.SyntaxKind.WhileStatement:
                 return this.transpileWhile(<ts.WhileStatement>node);
+            case ts.SyntaxKind.DoStatement:
+                return this.transpileDoStatement(<ts.DoStatement>node);
             case ts.SyntaxKind.ForStatement:
                 return this.transpileFor(<ts.ForStatement>node);
             case ts.SyntaxKind.ForOfStatement:
@@ -312,6 +314,19 @@ export class LuaTranspiler {
         return result + this.indent + "end\n";
     }
 
+    transpileDoStatement(node: ts.DoStatement): string {
+        let result = this.indent + `repeat\n`;
+
+        this.pushIndent();
+        result += this.transpileStatement(node.statement);
+        this.popIndent();
+
+        // Negate the expression because we translate from do-while to repeat-until (repeat-while-not)
+        result += this.indent + `until not ${this.transpileExpression(node.expression, true)}\n`;
+
+        return result;
+    }
+
     transpileFor(node: ts.ForStatement): string {
         // Get iterator variable
         const variable = (<ts.VariableDeclarationList>node.initializer).declarations[0];
diff --git a/test/src/util.ts b/test/src/util.ts
index 53f50d9aa..71ddd40b1 100644
--- a/test/src/util.ts
+++ b/test/src/util.ts
@@ -1,6 +1,8 @@
 import * as ts from "typescript";
 import * as path from "path";
 
+import { Expect } from "alsatian";
+
 import { LuaTranspiler, TranspileError } from "../../src/Transpiler";
 import { CompilerOptions } from "../../src/CommandLineParser";
 
@@ -60,6 +62,18 @@ export function executeLua(lua: string, withLib = true): any {
     return luavm.execute(lua)[0];
 }
 
+export function expectCodeEqual(code1: string, code2: string) {
+    // Trim leading/trailing whitespace
+    let c1 = code1.trim();
+    let c2 = code2.trim();
+
+    // Unify indentation
+    c1 = c1.replace(/\s+/g, " ");
+    c2 = c2.replace(/\s+/g, " ");
+
+    Expect(c1).toBe(c2);
+}
+
 const lualib = fs.readFileSync("dist/lualib/typescript.lua") + "\n";
 
 const jsonlib = fs.readFileSync("test/src/json.lua") + "\n";
diff --git a/test/unit/while.spec.ts b/test/unit/while.spec.ts
new file mode 100644
index 000000000..29f9e3295
--- /dev/null
+++ b/test/unit/while.spec.ts
@@ -0,0 +1,33 @@
+import { Expect, Test, TestCase, FocusTest } from "alsatian";
+import * as util from "../src/util";
+
+export class WhileTests {
+
+    @Test("While loop")
+    public defaultWhile() {
+        const input = `declare var a: number;
+        while (a < 10) {
+            a++;
+        }`;
+
+        const expected = `while a<10 do
+            a=a+1
+        end`;
+
+        util.expectCodeEqual(util.transpileString(input), expected);
+    }
+
+    @Test("Do While")
+    public doWhile() {
+        const input = `declare var a: number;
+        do {
+            a++;
+        } while (a < 10);`;
+
+        const expected = `repeat
+            a=a+1
+        until not (a<10)`;
+
+        util.expectCodeEqual(util.transpileString(input), expected);
+    }
+}