fix: return original source when no inline styles are found

[arkthur]

Problem

When stylelint runs with --fix on an Angular .ts file that uses styleUrl (external stylesheet) — or any plain .ts file with no inline styles — the stringifier produces an empty string. Stylelint writes that empty string back to disk, erasing the entire file.

Reported in issue #6.

Root cause

Parser: the PostCSS document root is created by postcss.parse("", { from }) — an empty string. The original TypeScript source is never stored anywhere on the PostCSS tree.

Stringifier: iterates over node.root().nodes. When there are no inline styles, nodes is an empty array, forEach never executes, builder is never called, and the output is "". The attempted fallback node.source?.input?.css also returns "" because the root was parsed from an empty string, not the original source.

Stylelint then writes "" back to disk.

The CLI accidentally avoids overwriting because it skips the write step when result.code is falsy. The VS Code stylelint extension replaces the full document content unconditionally, so it is always affected.

Fix

Parser — store the original TypeScript source in document.raws.angularSource before returning:

+document.raws.angularSource = sourceString;

Stringifier — when nodes is empty, read root.raws.angularSource and return the original source unchanged:

-node.root().nodes.forEach((node) => {
-  builder(node.raws.angularCodeBefore, node);
-  postcssStringify(node, builder);
-  builder(node.raws.angularCodeAfter, node);
-});
+const root = node.root();
+const nodes = root.nodes;
+
+if (nodes.length === 0) {
+  builder(root.raws.angularSource ?? "");
+  return;
+}
+
+nodes.forEach((node) => {
+  builder(node.raws.angularCodeBefore, node);
+  postcssStringify(node, builder);
+  builder(node.raws.angularCodeAfter, node);
+});