From 7046854f6300ab1510741aed793c950217f7194b Mon Sep 17 00:00:00 2001
From: Knut Wannheden <knut@moderne.io>
Date: Mon, 30 Sep 2024 12:16:19 +0200
Subject: [PATCH] Basic support for `if`

The `else` part is not yet covered.
---
 openrewrite/src/javascript/parser.ts          | 30 +++++++++++++++++--
 openrewrite/test/javascript/parser/if.test.ts | 13 ++++++++
 2 files changed, 41 insertions(+), 2 deletions(-)
 create mode 100644 openrewrite/test/javascript/parser/if.test.ts

diff --git a/openrewrite/src/javascript/parser.ts b/openrewrite/src/javascript/parser.ts
index 4c86960a..ba9f3a86 100644
--- a/openrewrite/src/javascript/parser.ts
+++ b/openrewrite/src/javascript/parser.ts
@@ -215,7 +215,7 @@ export class JavaScriptParserVisitor {
 
     private semicolonPaddedStatementList(statements: ts.NodeArray<ts.Statement>) {
         return this.rightPaddedList([...statements], this.semicolonPrefix, n => {
-            const last = n.getLastToken();
+            const last = n.getChildAt(n.getChildCount(this.sourceFile) - 1, this.sourceFile);
             return last?.kind == ts.SyntaxKind.SemicolonToken ? Markers.build([new Semicolon(randomId())]) : Markers.EMPTY;
         });
     }
@@ -1193,7 +1193,24 @@ export class JavaScriptParserVisitor {
     }
 
     visitIfStatement(node: ts.IfStatement) {
-        return this.visitUnknown(node);
+        const semicolonAfterThen = node.thenStatement.getLastToken()?.kind == ts.SyntaxKind.SemicolonToken;
+        return new J.If(
+            randomId(),
+            this.prefix(node),
+            Markers.EMPTY,
+            new J.ControlParentheses(
+                randomId(),
+                this.prefix(this.findChildNode(node, ts.SyntaxKind.OpenParenToken)!),
+                Markers.EMPTY,
+                this.rightPadded(this.visit(node.expression), this.suffix(node.expression))
+            ),
+            this.rightPadded(
+                this.convert(node.thenStatement),
+                semicolonAfterThen ? this.prefix(node.thenStatement.getLastToken()!) : Space.EMPTY,
+                semicolonAfterThen ? Markers.build([new Semicolon(randomId())]) : Markers.EMPTY
+            ),
+            node.elseStatement ? this.visit(node.elseStatement) : null
+        );
     }
 
     visitDoStatement(node: ts.DoStatement) {
@@ -1828,6 +1845,15 @@ export class JavaScriptParserVisitor {
             this.prefix(nodes[nodes.length - 1])
         );
     }
+
+    private findChildNode(node: ts.Node, kind: ts.SyntaxKind): ts.Node | undefined {
+        for (let i = 0; i < node.getChildCount(); i++) {
+            if (node.getChildAt(i).kind == kind) {
+                return node.getChildAt(i);
+            }
+        }
+        return undefined;
+    }
 }
 
 function prefixFromNode(node: ts.Node, sourceFile: ts.SourceFile): Space {
diff --git a/openrewrite/test/javascript/parser/if.test.ts b/openrewrite/test/javascript/parser/if.test.ts
new file mode 100644
index 00000000..1444d2a6
--- /dev/null
+++ b/openrewrite/test/javascript/parser/if.test.ts
@@ -0,0 +1,13 @@
+import {connect, disconnect, rewriteRun, typeScript} from '../testHarness';
+
+describe('if mapping', () => {
+    beforeAll(() => connect());
+    afterAll(() => disconnect());
+
+    test('simple', () => {
+        rewriteRun(
+          //language=typescript
+          typeScript('if (true) console.log("foo");')
+        );
+    });
+});