fix(context): preserve packages when replacement fails (#142)

.changeset/calm-badgers-rebuild.md

@@ -0,0 +1,5 @@
+---
+"@neuledge/context": patch
+---
+
+Preserve installed documentation when a rebuild or install fails. Stage and validate replacements before renaming them into place, and keep temporary databases out of package discovery.

packages/context/README.md

@@ -297,6 +297,12 @@ context add ./my-project --name my-lib --pkg-version 2.0 --save ./packages/
 context add ./packages/my-lib@2.0.db
 ```
 
+Rebuilds and installs stage a replacement beside the destination, then close and
+validate it before replacing the installed package. A failed build, download, or
+replacement leaves the previous package available. Temporary files are excluded
+from package discovery. If the operating system blocks replacement of an open
+file (for example, on Windows), close the reader and retry the install.
+
 ---
 
 ## :whale: Docker

packages/context/src/cli.ts

@@ -1,12 +1,9 @@
 #!/usr/bin/env node
 
 import {
-  copyFileSync,
   createWriteStream,
   existsSync,
   mkdirSync,
-  readdirSync,
-  renameSync,
   statSync,
   unlinkSync,
 } from "node:fs";
@@ -55,11 +52,13 @@ import {
   buildPackage,
   type MarkdownFile,
 } from "./package-builder.js";
+import { copyPackageFile, createPackageTempFile } from "./package-file.js";
 import { type SearchResult, search } from "./search.js";
 import { ContextServer } from "./server.js";
 import {
   getPackageFileName,
   isAllowedLibrary,
+  loadPackages,
   type PackageInfo,
   PackageStore,
   packageKey,
@@ -497,7 +496,7 @@ function savePackageCopy(
     destPath = join(resolvedSavePath, getPackageFileName(packageName, version));
   }
 
-  copyFileSync(sourcePath, destPath);
+  copyPackageFile(sourcePath, destPath);
   console.log(`✓ Saved to ${destPath}`);
 }
 
@@ -506,21 +505,6 @@ function ensureDataDir(): void {
   mkdirSync(DATA_DIR, { recursive: true });
 }
 
-/** Load all packages from the data directory into the store. */
-function loadPackages(store: PackageStore): void {
-  if (!existsSync(DATA_DIR)) return;
-
-  for (const file of readdirSync(DATA_DIR)) {
-    if (!file.endsWith(".db")) continue;
-    try {
-      const info = readPackageInfo(join(DATA_DIR, file));
-      store.add(info);
-    } catch {
-      // Skip invalid packages
-    }
-  }
-}
-
 /**
  * Report a finished install.
  *
@@ -562,7 +546,7 @@ function reportInstalled(pkg: {
   );
 
   const store = new PackageStore();
-  loadPackages(store);
+  loadPackages(store, DATA_DIR);
   const preferred = store.get(pkg.name);
   if (!preferred || preferred.version === pkg.version) return;
 
@@ -648,7 +632,7 @@ function addFromFile(source: string, options: { save?: string }): void {
   const destPath = join(DATA_DIR, destName);
 
   if (resolve(sourcePath) !== destPath) {
-    copyFileSync(sourcePath, destPath);
+    copyPackageFile(sourcePath, destPath);
     console.log(`✓ Copied to ${destPath}`);
     info.path = destPath;
   }
@@ -668,47 +652,26 @@ async function addFromUrl(
 ): Promise<void> {
   console.log(`Downloading ${url}...`);
 
-  // Extract filename from URL for temp file
-  const urlObj = new URL(url);
-  const filename = basename(urlObj.pathname) || "package.db";
-
   // Download to temp location first
   ensureDataDir();
-  const tempPath = join(DATA_DIR, `.downloading-${Date.now()}-${filename}`);
+  const temp = createPackageTempFile(DATA_DIR);
 
   try {
-    await downloadFile(url, tempPath);
+    await downloadFile(url, temp.path);
     console.log(`✓ Downloaded`);
 
     // Validate the package
-    const info = readPackageInfo(tempPath);
+    const info = temp.install();
     console.log(`✓ Validated package`);
 
-    // Move to final location
-    const destName = getPackageFileName(info.name, info.version);
-    const destPath = join(DATA_DIR, destName);
-
-    // Remove old version if it exists
-    if (existsSync(destPath)) {
-      unlinkSync(destPath);
-    }
-
-    // Rename temp to final
-    renameSync(tempPath, destPath);
-    info.path = destPath;
-
     // Save to custom path if specified
     if (options.save) {
-      savePackageCopy(destPath, options.save, info.name, info.version);
+      savePackageCopy(info.path, options.save, info.name, info.version);
     }
 
     reportInstalled(info);
-  } catch (err) {
-    // Clean up temp file on error
-    if (existsSync(tempPath)) {
-      unlinkSync(tempPath);
-    }
-    throw err;
+  } finally {
+    temp.cleanup();
   }
 }
 
@@ -1088,7 +1051,7 @@ program
   .description("Show installed packages")
   .action(() => {
     const store = new PackageStore();
-    loadPackages(store);
+    loadPackages(store, DATA_DIR);
     const packages = store.list();
 
     if (packages.length === 0) {
@@ -1158,7 +1121,7 @@ program
   .argument("<name>", "Package name (e.g., 'next' or 'next@v16.2.0')")
   .action((name: string) => {
     const store = new PackageStore();
-    loadPackages(store);
+    loadPackages(store, DATA_DIR);
 
     const target = resolveRemoveTarget(name, store.list());
     if ("error" in target) {
@@ -1196,7 +1159,7 @@ program
       libs?: string[];
     }) => {
       const store = new PackageStore();
-      loadPackages(store);
+      loadPackages(store, DATA_DIR);
 
       const allowedLibraries = options.libs
         ? resolveAllowedLibraries(options.libs, store.list())
@@ -1265,7 +1228,7 @@ program
   .argument("<topic>", GET_DOCS_TOPIC_DESCRIPTION)
   .action((library: string, topic: string) => {
     const store = new PackageStore();
-    loadPackages(store);
+    loadPackages(store, DATA_DIR);
 
     const packages = store.list();
     const pkg = store.get(library);