fix(core): more detailed error message when version cannot be found

packages/core/src/__tests__/command.spec.ts

@@ -384,6 +384,36 @@ describe('core-command', () => {
         })
       );
     });
+
+    it('throws ENOVERSION when lerna.json is empty', async () => {
+      const cwd = await initFixture('basic');
+
+      const lernaConfigPath = path.join(cwd, 'lerna.json');
+      await fs.writeJson(lernaConfigPath, {});
+
+      await expect(testFactory({ cwd })).rejects.toThrow(
+        expect.objectContaining({
+          prefix: 'ENOVERSION',
+        })
+      );
+    });
+
+    it('throws ENOVERSION when no version property exists in lerna.json', async () => {
+      const cwd = await initFixture('basic');
+
+      const lernaConfigPath = path.join(cwd, 'lerna.json');
+      const lernaConfig = await fs.readJson(lernaConfigPath);
+      delete lernaConfig.version;
+      await fs.writeJson(lernaConfigPath, {
+        ...lernaConfig,
+      });
+
+      await expect(testFactory({ cwd })).rejects.toThrow(
+        expect.objectContaining({
+          prefix: 'ENOVERSION',
+        })
+      );
+    });
   });
 
   describe('loglevel with verbose option true', () => {

packages/core/src/command.ts

@@ -285,11 +285,12 @@ export class Command<T extends AvailableCommandOption> {
       );
     }
 
+    if (this.project.configNotFound) {
+      throw new ValidationError('ENOLERNA', '`lerna.json` does not exist, have you run `lerna init`?');
+    }
+
     if (!this.project.version) {
-      throw new ValidationError(
-        'ENOLERNA',
-        'No `lerna.json` file exist, please create one in the root of your project.'
-      );
+      throw new ValidationError('ENOVERSION', 'Required property version does not exist in `lerna.json`');
     }
 
     if ((this.options as InitCommandOption).independent && !this.project.isIndependent()) {

packages/core/src/project/project.ts

@@ -22,6 +22,7 @@ import { ProjectConfig, RawManifest } from '../models';
  */
 export class Project {
   config: ProjectConfig;
+  configNotFound: boolean;
   rootConfigLocation: string;
   rootPath: string;
   static PACKAGE_GLOB = 'packages/*';
@@ -40,6 +41,7 @@ export class Project {
             // No need to distinguish between missing and empty,
             // saves a lot of noisy guards elsewhere
             config: {},
+            configNotFound: true,
             // path.resolve(".", ...) starts from process.cwd()
             filepath: path.resolve(cwd || '.', 'lerna.json'),
           };
@@ -66,6 +68,7 @@ export class Project {
     }
 
     this.config = loaded?.config;
+    this.configNotFound = loaded?.configNotFound;
     this.rootConfigLocation = loaded?.filepath ?? '';
     this.rootPath = path.dirname(loaded?.filepath ?? '');