Added string.substr

Perryvw · Perryvw · commit 5d563b63ffea · 2018-07-20T14:26:12.000+02:00
diff --git a/src/Transpiler.ts b/src/Transpiler.ts
@@ -1009,6 +1009,14 @@ export abstract class LuaTranspiler {
                 } else {
                     return `(string.find(${caller},${params}+1,true) or 0)-1`;
                 }
+            case "substr":
+                if (node.arguments.length === 1) {
+                    return `string.sub(${caller},${params}+1)`;
+                } else {
+                    const arg1 = this.transpileExpression(node.arguments[0]);
+                    const arg2 = this.transpileExpression(node.arguments[1]);
+                    return `string.sub(${caller},${arg1}+1,${arg1}+${arg2})`;
+                }
             case "substring":
                 if (node.arguments.length === 1) {
                     return `string.sub(${caller},${params}+1)`;
diff --git a/test/unit/string.spec.ts b/test/unit/string.spec.ts
@@ -146,6 +146,25 @@ export class StringTests {
         Expect(result).toBe(inp.substring(start, end));
     }
 
+    @TestCase("hello test", 0)
+    @TestCase("hello test", 1)
+    @TestCase("hello test", 1, 2)
+    @TestCase("hello test", 1, 5)
+    @Test("string.substring")
+    public substr(inp: string, start: number, end?: number) {
+        // Transpile
+        const paramStr = end ? `${start}, ${end}` : `${start}`;
+        const lua = util.transpileString(
+            `return "${inp}".substr(${paramStr})`
+        );
+
+        // Execute
+        const result = util.executeLua(lua);
+
+        // Assert
+        Expect(result).toBe(inp.substr(start, end));
+    }
+
     @TestCase("", 0)
     @TestCase("h", 1)
     @TestCase("hello", 5)
