Address workspace diff review findings

Co-Authored-By: Paperclip <noreply@paperclip.ing>

server/src/__tests__/workspace-diff-service.test.ts

@@ -91,6 +91,7 @@ describe("workspaceDiffService", () => {
     await fs.rm(path.join(repoRoot, "delete-me.txt"));
     await fs.writeFile(path.join(repoRoot, "binary.bin"), Buffer.from([0, 1, 2, 3, 4, 5]));
     await fs.writeFile(path.join(repoRoot, "untracked.txt"), "brand new\n", "utf8");
+    await fs.writeFile(path.join(repoRoot, "empty-untracked.txt"), "", "utf8");
     await fs.writeFile(path.join(repoRoot, "oversized.txt"), "x".repeat(WORKSPACE_DIFF_CAPS.maxFileBytes + 1), "utf8");
 
     const diff = await workspaceDiffService().getDiff(createWorkspace(repoRoot), workingTreeQuery());
@@ -126,6 +127,13 @@ describe("workspaceDiffService", () => {
       additions: 1,
     });
     expect(byPath.get("untracked.txt")?.patches[0]?.patch).toContain("+brand new");
+    expect(byPath.get("empty-untracked.txt")?.patches[0]?.patch).toBe([
+      "diff --git a/empty-untracked.txt b/empty-untracked.txt",
+      "new file mode 100644",
+      "--- /dev/null",
+      "+++ b/empty-untracked.txt",
+      "",
+    ].join("\n"));
     expect(byPath.get("binary.bin")).toMatchObject({
       binary: true,
       unstaged: true,

server/src/services/plugin-host-services.ts

@@ -571,6 +571,11 @@ export function buildHostServices(
    */
   const ensurePluginAvailableForCompany = async (_companyId: string) => {};
 
+  const ensureDeclaredCapability = (capability: import("@paperclipai/shared").PluginCapability) => {
+    if (!options.manifest || options.manifest.capabilities.includes(capability)) return;
+    throw new Error(`Missing required capability: ${capability}`);
+  };
+
   const getLocalFolderDeclaration = (folderKey: string) =>
     requireLocalFolderDeclaration(options.manifest?.localFolders, folderKey);
 
@@ -1227,6 +1232,7 @@ export function buildHostServices(
         if (!projectWorkspace) {
           throw new Error("Workspace not found");
         }
+        ensureDeclaredCapability("project.workspaces.read");
         return workspaceDiff.getDiff({
           id: projectWorkspace.id,
           companyId: projectWorkspace.companyId,

server/src/services/workspace-diff.ts

@@ -442,17 +442,16 @@ function countAddedLines(content: string) {
 function buildUntrackedPatch(filePath: string, content: string) {
   const lines = content.length === 0 ? [] : content.split("\n");
   if (lines.length > 0 && lines[lines.length - 1] === "") lines.pop();
-  const hunkLines = lines.map((line) => `+${line}`).join("\n");
   const lineCount = countAddedLines(content);
-  return [
+  const header = [
     `diff --git a/${filePath} b/${filePath}`,
     "new file mode 100644",
     "--- /dev/null",
     `+++ b/${filePath}`,
-    `@@ -0,0 +1,${lineCount} @@`,
-    hunkLines,
-    "",
-  ].join("\n");
+  ];
+  if (lineCount === 0) return `${header.join("\n")}\n`;
+  const hunkLines = lines.map((line) => `+${line}`).join("\n");
+  return [...header, `@@ -0,0 +1,${lineCount} @@`, hunkLines, ""].join("\n");
 }
 
 async function buildUntrackedFilePatch(input: {
@@ -674,8 +673,6 @@ export function workspaceDiffService() {
       return {
         workspaceId: workspace.id,
         companyId: workspace.companyId,
-        repoRoot,
-        cwd,
         view: query.view,
         baseRef,
         headSha: await resolveHeadSha(cwd),