feat(bootstrap): Add --strict option to enable throwing when `--hoi…

…st` warns (#2140)

commands/bootstrap/README.md

@@ -56,6 +56,14 @@ For background on `--hoist`, see the [hoist documentation](https://github.com/le
 Note: If packages depend on different _versions_ of an external dependency,
 the most commonly used version will be hoisted, and a warning will be emitted.
 
+### --strict
+
+When used in conjunction with hoist will throw an error and stop bootstrapping after emitting the version warnings. Has no effect if you aren't hoisting, or if there are no version warnings.
+
+```sh
+$ lerna bootstrap --hoist --strict
+```
+
 ### --nohoist [glob]
 
 Do _not_ install external dependencies matching `glob` at the repo root. This

commands/bootstrap/__tests__/bootstrap-command.test.js

@@ -208,6 +208,20 @@ describe("BootstrapCommand", () => {
     });
   });
 
+  describe("with --hoist and --strict", () => {
+    it("should throw if there's a hoist warning", async () => {
+      expect.assertions(1);
+
+      const testDir = await initFixture("basic");
+
+      try {
+        await lernaBootstrap(testDir)("--hoist", "--strict");
+      } catch (err) {
+        expect(err.message).toMatch("Package version inconsistencies found");
+      }
+    });
+  });
+
   describe("with --ci", () => {
     it("should call npmInstall with ci subCommand if on npm 5.7.0 or later", async () => {
       const testDir = await initFixture("ci");

commands/bootstrap/command.js

@@ -53,6 +53,11 @@ exports.builder = yargs => {
         type: "string",
         requiresArg: true,
       },
+      strict: {
+        group: "Command Options:",
+        describe: "Don't allow warnings when hoisting as it causes longer bootstrap times and other issues.",
+        type: "boolean",
+      },
     });
 
   return filterable(yargs);

commands/bootstrap/index.js

@@ -373,6 +373,8 @@ class BootstrapCommand extends Command {
 
     const rootActions = [];
     const leafActions = [];
+    // We don't want to exit on the first hoist issue, but log them all and then exit
+    let strictExitOnWarning = false;
 
     // determine where each dependency will be installed
     for (const [externalName, externalDependents] of depsToInstall) {
@@ -394,6 +396,9 @@ class BootstrapCommand extends Command {
             `The repository root depends on ${externalName}@${rootVersion}, ` +
               `which differs from the more common ${externalName}@${commonVersion}.`
           );
+          if (this.options.strict) {
+            strictExitOnWarning = true;
+          }
         }
 
         const dependents = Array.from(externalDependents.get(rootVersion)).map(
@@ -427,6 +432,9 @@ class BootstrapCommand extends Command {
               `"${leafName}" package depends on ${externalName}@${leafVersion}, ` +
                 `which differs from the hoisted ${externalName}@${rootVersion}.`
             );
+            if (this.options.strict) {
+              strictExitOnWarning = true;
+            }
           }
 
           const leafNode = this.targetGraph.get(leafName);
@@ -444,6 +452,12 @@ class BootstrapCommand extends Command {
         }
       }
     }
+    if (this.options.strict && strictExitOnWarning) {
+      throw new ValidationError(
+        "EHOISTSTRICT",
+        "Package version inconsistencies found while hoisting. Fix the above warnings and retry."
+      );
+    }
 
     return pMapSeries([...rootActions, ...leafActions], el => el()).then(() => {
       this.logger.silly("root dependencies", JSON.stringify(rootSet, null, 2));