From c4fa93e460f5eddda5a48da0b996dc5e46f25e53 Mon Sep 17 00:00:00 2001
From: roboomp <omp@can.ac>
Date: Fri, 5 Jun 2026 07:59:28 +0000
Subject: [PATCH] fix(plugins): preserved null package import exclusions

Kept explicit null package imports as exclusions so exact entries and active conditions do not fall through to wildcard or fallback targets.\n\nFixes #1889
---
 .../extensibility/plugins/legacy-pi-compat.ts |  24 +++--
 .../test/plugin-extensions-discovery.test.ts  | 102 ++++++++++++++++++
 2 files changed, 119 insertions(+), 7 deletions(-)

diff --git a/packages/coding-agent/src/extensibility/plugins/legacy-pi-compat.ts b/packages/coding-agent/src/extensibility/plugins/legacy-pi-compat.ts
index 8ecf04a6f..70817b916 100644
--- a/packages/coding-agent/src/extensibility/plugins/legacy-pi-compat.ts
+++ b/packages/coding-agent/src/extensibility/plugins/legacy-pi-compat.ts
@@ -49,6 +49,7 @@ const SOURCE_MODULE_EXTENSIONS = [".ts", ".tsx", ".mts", ".cts", ".js", ".jsx",
 const SUPPORTED_PACKAGE_IMPORT_CONDITIONS = new Set(["bun", "node", "import", "default"]);
 const packageRootCache = new Map<string, string | null>();
 const packageImportsCache = new Map<string, Record<string, unknown> | null>();
+const PACKAGE_IMPORT_EXCLUDED = Symbol("packageImportExcluded");
 
 // Extensions that imported `@sinclair/typebox` directly used to resolve against a
 // real `@sinclair/typebox` install. The runtime dep was replaced with the Zod-backed
@@ -334,14 +335,20 @@ async function readPackageImports(packageRoot: string): Promise<Record<string, u
 	return imports;
 }
 
-function selectPackageImportTarget(entry: unknown): string | null {
+type PackageImportTargetSelection = string | typeof PACKAGE_IMPORT_EXCLUDED | null;
+type ResolvedPackageImportTargetSelection = string | typeof PACKAGE_IMPORT_EXCLUDED;
+
+function selectPackageImportTarget(entry: unknown): PackageImportTargetSelection {
+	if (entry === null) {
+		return PACKAGE_IMPORT_EXCLUDED;
+	}
 	if (typeof entry === "string") {
 		return entry;
 	}
 	if (Array.isArray(entry)) {
 		for (const item of entry) {
 			const target = selectPackageImportTarget(item);
-			if (target) return target;
+			if (target !== null) return target;
 		}
 		return null;
 	}
@@ -353,7 +360,7 @@ function selectPackageImportTarget(entry: unknown): string | null {
 			continue;
 		}
 		const target = selectPackageImportTarget(value);
-		if (target) return target;
+		if (target !== null) return target;
 	}
 	return null;
 }
@@ -386,11 +393,14 @@ async function resolvePackageImportSpecifier(specifier: string, importerPath: st
 	}
 
 	const exactTarget = selectPackageImportTarget(imports[specifier]);
-	if (exactTarget) {
+	if (exactTarget === PACKAGE_IMPORT_EXCLUDED) {
+		return null;
+	}
+	if (exactTarget !== null) {
 		return resolvePackageImportTarget(packageRoot, exactTarget, null);
 	}
 
-	let bestMatch: { keyLength: number; target: string; wildcard: string } | null = null;
+	let bestMatch: { keyLength: number; target: ResolvedPackageImportTargetSelection; wildcard: string } | null = null;
 	for (const [key, entry] of Object.entries(imports)) {
 		const starIndex = key.indexOf("*");
 		if (starIndex === -1) continue;
@@ -402,7 +412,7 @@ async function resolvePackageImportSpecifier(specifier: string, importerPath: st
 		}
 
 		const target = selectPackageImportTarget(entry);
-		if (!target) {
+		if (target === null) {
 			continue;
 		}
 
@@ -415,7 +425,7 @@ async function resolvePackageImportSpecifier(specifier: string, importerPath: st
 		}
 	}
 
-	if (!bestMatch) {
+	if (!bestMatch || bestMatch.target === PACKAGE_IMPORT_EXCLUDED) {
 		return null;
 	}
 	return resolvePackageImportTarget(packageRoot, bestMatch.target, bestMatch.wildcard);
diff --git a/packages/coding-agent/test/plugin-extensions-discovery.test.ts b/packages/coding-agent/test/plugin-extensions-discovery.test.ts
index 7858b3365..d429cda0a 100644
--- a/packages/coding-agent/test/plugin-extensions-discovery.test.ts
+++ b/packages/coding-agent/test/plugin-extensions-discovery.test.ts
@@ -308,6 +308,108 @@ describe("plugin extension discovery", () => {
 		expect(extension?.commands.has("json-schema-ext")).toBe(true);
 	});
 
+	it("preserves exact null package import exclusions ahead of wildcard fallbacks", async () => {
+		const pluginsDir = getPluginsDir();
+		const pluginDir = path.join(pluginsDir, "node_modules", "null-exact-import-plugin");
+		const extensionPath = path.join(pluginDir, "src", "index.ts");
+		fs.rmSync(path.join(pluginsDir, "node_modules"), { recursive: true, force: true });
+		fs.mkdirSync(path.join(pluginDir, "src"), { recursive: true });
+		fs.writeFileSync(
+			path.join(pluginsDir, "package.json"),
+			JSON.stringify({
+				name: "omp-plugins",
+				private: true,
+				dependencies: {
+					"null-exact-import-plugin": "1.0.0",
+				},
+			}),
+		);
+		fs.writeFileSync(
+			path.join(pluginDir, "package.json"),
+			JSON.stringify({
+				name: "null-exact-import-plugin",
+				version: "1.0.0",
+				imports: {
+					"#src/internal": null,
+					"#src/*": "./src/*",
+				},
+				pi: {
+					extensions: ["./src/index.ts"],
+				},
+			}),
+		);
+		fs.writeFileSync(path.join(pluginDir, "src", "internal.ts"), 'export const commandName = "null-exact-ext";');
+		fs.writeFileSync(
+			extensionPath,
+			[
+				'import { commandName } from "#src/internal";',
+				"",
+				"export default function(pi) {",
+				"\tpi.registerCommand(commandName, { handler: async () => {} });",
+				"}",
+			].join("\n"),
+		);
+
+		const result = await discoverAndLoadExtensions([], projectDir.path());
+		const extension = result.extensions.find(ext => ext.path === extensionPath);
+		const pluginError = result.errors.find(err => err.path === extensionPath);
+
+		expect(pluginError?.error).toContain("#src/internal");
+		expect(extension).toBeUndefined();
+	});
+
+	it("preserves active null conditional package import exclusions", async () => {
+		const pluginsDir = getPluginsDir();
+		const pluginDir = path.join(pluginsDir, "node_modules", "null-conditional-import-plugin");
+		const extensionPath = path.join(pluginDir, "src", "index.ts");
+		fs.rmSync(path.join(pluginsDir, "node_modules"), { recursive: true, force: true });
+		fs.mkdirSync(path.join(pluginDir, "src"), { recursive: true });
+		fs.writeFileSync(
+			path.join(pluginsDir, "package.json"),
+			JSON.stringify({
+				name: "omp-plugins",
+				private: true,
+				dependencies: {
+					"null-conditional-import-plugin": "1.0.0",
+				},
+			}),
+		);
+		fs.writeFileSync(
+			path.join(pluginDir, "package.json"),
+			JSON.stringify({
+				name: "null-conditional-import-plugin",
+				version: "1.0.0",
+				imports: {
+					"#blocked": {
+						node: null,
+						default: "./src/blocked.ts",
+					},
+				},
+				pi: {
+					extensions: ["./src/index.ts"],
+				},
+			}),
+		);
+		fs.writeFileSync(path.join(pluginDir, "src", "blocked.ts"), 'export const commandName = "null-conditional-ext";');
+		fs.writeFileSync(
+			extensionPath,
+			[
+				'import { commandName } from "#blocked";',
+				"",
+				"export default function(pi) {",
+				"\tpi.registerCommand(commandName, { handler: async () => {} });",
+				"}",
+			].join("\n"),
+		);
+
+		const result = await discoverAndLoadExtensions([], projectDir.path());
+		const extension = result.extensions.find(ext => ext.path === extensionPath);
+		const pluginError = result.errors.find(err => err.path === extensionPath);
+
+		expect(pluginError?.error).toContain("#blocked");
+		expect(extension).toBeUndefined();
+	});
+
 	it("rewrites side-effect imports of package-import aliases and legacy Pi scopes", async () => {
 		const pluginsDir = getPluginsDir();
 		const pluginDir = path.join(pluginsDir, "node_modules", "side-effect-plugin");