fix(project): Report syntax errors in root package.json

Fixes #1452

core/command/__tests__/command.test.js

@@ -448,6 +448,23 @@ describe("core-command", () => {
       }
     });
 
+    it("throws JSONError when root package.json has syntax error", async () => {
+      expect.assertions(1);
+
+      const cwd = await initFixture("basic");
+
+      await fs.writeFile(
+        path.join(cwd, "package.json"), // trailing comma ...v
+        '{ "name": "invalid", "lerna": { "version": "1.0.0" }, }'
+      );
+
+      try {
+        await testFactory({ cwd });
+      } catch (err) {
+        expect(err.prefix).toBe("JSONError");
+      }
+    });
+
     it("throws ENOLERNA when lerna.json is not found", async () => {
       expect.assertions(1);
 

core/project/__fixtures__/pkg-prop-syntax-error/package.json

@@ -0,0 +1,14 @@
+{
+  "name": "pkg-prop-syntax-error",
+  "version": "0.0.0-root",
+  "private": true,
+  "lerna": {
+    "loglevel": "success",
+    "command": {
+      "publish": {
+        "loglevel": "verbose"
+      }
+    },
+    "version": "1.0.0"
+  },,
+}

core/project/__tests__/project.test.js

@@ -85,6 +85,19 @@ describe("Project", () => {
       });
     });
 
+    it("errors when root package.json is not valid JSON", async () => {
+      expect.assertions(2);
+
+      const cwd = await initFixture("pkg-prop-syntax-error");
+
+      try {
+        const project = new Project(cwd); // eslint-disable-line no-unused-vars
+      } catch (err) {
+        expect(err.name).toBe("ValidationError");
+        expect(err.prefix).toBe("JSONError");
+      }
+    });
+
     it("extends local shared config", async () => {
       const cwd = await initFixture("extends");
       const project = new Project(cwd);

core/project/index.js

@@ -111,7 +111,11 @@ class Project {
         value: manifest,
       });
     } catch (err) {
-      // syntax errors are already caught and reported by constructor
+      // redecorate JSON syntax errors, avoid debug dump
+      if (err.name === "JSONError") {
+        throw new ValidationError(err.name, err.message);
+      }
+
       // try again next time
     }