Add back error messages when unable to detect workspaces (#586)

Author: bmish

lib/package.ts

@@ -38,9 +38,15 @@ export class Package {
     if (this.packageJson.workspaces) {
       if (Array.isArray(this.packageJson.workspaces)) {
         return this.packageJson.workspaces;
-      }
-      if (this.packageJson.workspaces.packages) {
+      } else if (this.packageJson.workspaces.packages) {
+        if (!Array.isArray(this.packageJson.workspaces.packages)) {
+          throw new TypeError(
+            'package.json `workspaces.packages` is not a string array.'
+          );
+        }
         return this.packageJson.workspaces.packages;
+      } else {
+        throw new TypeError('package.json `workspaces` is not a string array.');
       }
     }
     return [];

lib/workspace.ts

@@ -1,6 +1,4 @@
 import { join } from 'node:path';
-import { existsSync, readFileSync } from 'node:fs';
-import type { PackageJson } from 'type-fest';
 import { globbySync } from 'globby';
 import { Package } from './package.js';
 
@@ -11,6 +9,15 @@ export function getPackages(
   ignorePaths: string[],
   ignorePathPatterns: RegExp[]
 ): Package[] {
+  // Check for some error cases first.
+  if (!Package.exists(root)) {
+    throw new Error('No package.json found at provided path.');
+  }
+  const package_ = new Package(root, root);
+  if (package_.workspacePatterns.length === 0) {
+    throw new Error('Package at provided path has no workspaces specified.');
+  }
+
   const packages = accumulatePackages(root, ['.']);
 
   for (const ignoredPackage of ignorePackages) {
@@ -86,38 +93,6 @@ export function getPackages(
   return packages;
 }
 
-export function getWorkspaces(root: string): string[] {
-  const workspacePackageJsonPath = join(root, 'package.json');
-  if (!existsSync(workspacePackageJsonPath)) {
-    throw new Error('No package.json found at provided path.');
-  }
-
-  const workspacePackageJson: PackageJson = JSON.parse(
-    readFileSync(join(root, 'package.json'), 'utf8')
-  );
-
-  if (!workspacePackageJson.workspaces) {
-    throw new Error(
-      'package.json at provided path does not specify `workspaces`.'
-    );
-  }
-
-  if (!Array.isArray(workspacePackageJson.workspaces)) {
-    if (workspacePackageJson.workspaces.packages) {
-      if (Array.isArray(workspacePackageJson.workspaces.packages)) {
-        return workspacePackageJson.workspaces.packages;
-      } else {
-        throw new TypeError(
-          'package.json `workspaces.packages` is not a string array.'
-        );
-      }
-    }
-    throw new TypeError('package.json `workspaces` is not a string array.');
-  }
-
-  return workspacePackageJson.workspaces;
-}
-
 // Expand workspace globs into concrete paths.
 function expandWorkspaces(root: string, workspacePatterns: string[]): string[] {
   return workspacePatterns.flatMap((workspace) => {

test/lib/workspace-test.ts

@@ -1,4 +1,4 @@
-import { getPackages, getWorkspaces } from '../../lib/workspace.js';
+import { getPackages } from '../../lib/workspace.js';
 import { join } from 'node:path';
 import {
   FIXTURE_PATH_NOT_A_WORKSPACE,
@@ -33,6 +33,26 @@ describe('Utils | workspace', function () {
       );
     });
 
+    it('behaves correctly with valid fixture for using nohoist', function () {
+      expect(
+        getPackages(FIXTURE_PATH_VALID_WITH_PACKAGES, [], [], [], []).map(
+          (package_) => package_.path
+        )
+      ).toStrictEqual(
+        [
+          '.',
+          '@scope1/package1',
+          '@scope1/package2',
+          '@scope2/deps-only',
+          '@scope2/dev-deps-only',
+          'nested-scope/@nested-level/package',
+          'foo1',
+          'foo2',
+          'package1',
+        ].map((path) => join(FIXTURE_PATH_VALID_WITH_PACKAGES, path))
+      );
+    });
+
     it('filters out ignored package', function () {
       expect(
         getPackages(FIXTURE_PATH_VALID, ['@scope1/package1'], [], [], []).map(
@@ -179,61 +199,34 @@ describe('Utils | workspace', function () {
         )
       );
     });
-  });
-
-  describe('#getWorkspaces', function () {
-    it('behaves correctly with valid fixture', function () {
-      expect(getWorkspaces(FIXTURE_PATH_VALID)).toMatchInlineSnapshot(`
-        Array [
-          "@scope1/*",
-          "@scope2/*",
-          "nested-scope/**",
-          "foo*",
-          "package1",
-        ]
-      `);
-    });
-
-    it('behaves correctly with valid fixture for using nohoist', function () {
-      expect(getWorkspaces(FIXTURE_PATH_VALID_WITH_PACKAGES))
-        .toMatchInlineSnapshot(`
-          Array [
-            "@scope1/*",
-            "@scope2/*",
-            "nested-scope/**",
-            "foo*",
-            "package1",
-          ]
-        `);
-    });
 
     it('throws with fixture that has no package.json', function () {
       expect(() =>
-        getWorkspaces(FIXTURE_PATH_NO_PACKAGE_JSON)
+        getPackages(FIXTURE_PATH_NO_PACKAGE_JSON, [], [], [], [])
       ).toThrowErrorMatchingInlineSnapshot(
         '"No package.json found at provided path."'
       );
     });
 
     it('throws with fixture that does not have workspace specified', function () {
       expect(() =>
-        getWorkspaces(FIXTURE_PATH_NOT_A_WORKSPACE)
+        getPackages(FIXTURE_PATH_NOT_A_WORKSPACE, [], [], [], [])
       ).toThrowErrorMatchingInlineSnapshot(
-        '"package.json at provided path does not specify `workspaces`."'
+        '"Package at provided path has no workspaces specified."'
       );
     });
 
     it('throws with fixture that does not have workspace specified as array', function () {
       expect(() =>
-        getWorkspaces(FIXTURE_PATH_WORKSPACE_NOT_AN_ARRAY)
+        getPackages(FIXTURE_PATH_WORKSPACE_NOT_AN_ARRAY, [], [], [], [])
       ).toThrowErrorMatchingInlineSnapshot(
         '"package.json `workspaces` is not a string array."'
       );
     });
 
     it('throws with fixture that does not have workspace packages specified as array', function () {
       expect(() =>
-        getWorkspaces(FIXTURE_PATH_WORKSPACE_PACKAGE_NOT_AN_ARRAY)
+        getPackages(FIXTURE_PATH_WORKSPACE_PACKAGE_NOT_AN_ARRAY, [], [], [], [])
       ).toThrowErrorMatchingInlineSnapshot(
         '"package.json `workspaces.packages` is not a string array."'
       );