Remove optional peer dependencies

lib/packExternalModules.js

@@ -94,14 +94,32 @@ function getProdModules(externalModules, packagePath, dependencyGraph, forceExcl
         const peerDependencies = require(modulePackagePath).peerDependencies;
         if (!_.isEmpty(peerDependencies)) {
           this.options.verbose && this.serverless.cli.log(`Adding explicit peers for dependency ${module.external}`);
-          const peerModules = getProdModules.call(
-            this,
-            _.map(peerDependencies, (value, key) => ({ external: key })),
-            packagePath,
-            dependencyGraph,
-            forceExcludes
-          );
-          Array.prototype.push.apply(prodModules, peerModules);
+
+          const peerDependenciesMeta = require(modulePackagePath).peerDependenciesMeta;
+
+          if (!_.isEmpty(peerDependenciesMeta)) {
+            _.forEach(peerDependencies, (value, key) => {
+              if (peerDependenciesMeta[key] && peerDependenciesMeta[key].optional === true) {
+                this.options.verbose &&
+                  this.serverless.cli.log(
+                    `Skipping peers dependency ${key} for dependency ${module.external} because it's optional`
+                  );
+
+                _.unset(peerDependencies, key);
+              }
+            });
+          }
+
+          if (!_.isEmpty(peerDependencies)) {
+            const peerModules = getProdModules.call(
+              this,
+              _.map(peerDependencies, (value, key) => ({ external: key })),
+              packagePath,
+              dependencyGraph,
+              forceExcludes
+            );
+            Array.prototype.push.apply(prodModules, peerModules);
+          }
         }
       } catch (e) {
         this.serverless.cli.log(`WARNING: Could not check for peer dependencies of ${module.external}`);
@@ -424,3 +442,4 @@ module.exports = {
     });
   }
 };
+

tests/data/rp-package-optional.json

@@ -0,0 +1,94 @@
+{
+  "_from": "request-promise",
+  "_id": "[email protected]",
+  "_inBundle": false,
+  "_integrity": "sha1-fuxWyJMXqCLL/qmbA5zlQ8LhX2c=",
+  "_location": "/request-promise",
+  "_phantomChildren": {},
+  "_requested": {
+    "type": "tag",
+    "registry": true,
+    "raw": "request-promise",
+    "name": "request-promise",
+    "escapedName": "request-promise",
+    "rawSpec": "",
+    "saveSpec": null,
+    "fetchSpec": "latest"
+  },
+  "_requiredBy": [
+    "#USER",
+    "/"
+  ],
+  "_resolved": "https://registry.npmjs.org/request-promise/-/request-promise-4.2.1.tgz",
+  "_shasum": "7eec56c89317a822cbfea99b039ce543c2e15f67",
+  "_spec": "request-promise",
+  "_where": "C:\\Projects\\serverless\\test\\babel-dynamically-entries",
+  "author": {
+    "name": "Nicolai Kamenzky",
+    "url": "https://github.com/analog-nico"
+  },
+  "bugs": {
+    "url": "https://github.com/request/request-promise/issues"
+  },
+  "bundleDependencies": false,
+  "dependencies": {
+    "bluebird": "^3.5.0",
+    "request-promise-core": "1.1.1",
+    "stealthy-require": "^1.1.0",
+    "tough-cookie": ">=2.3.0"
+  },
+  "deprecated": false,
+  "description": "The simplified HTTP request client 'request' with Promise support. Powered by Bluebird.",
+  "devDependencies": {
+    "body-parser": "~1.15.2",
+    "chai": "~3.5.0",
+    "chalk": "~1.1.3",
+    "gulp": "~3.9.1",
+    "gulp-coveralls": "~0.1.4",
+    "gulp-eslint": "~2.1.0",
+    "gulp-istanbul": "~1.0.0",
+    "gulp-mocha": "~2.2.0",
+    "lodash": "~4.13.1",
+    "publish-please": "~2.1.4",
+    "request": "^2.34.0",
+    "rimraf": "~2.5.3",
+    "run-sequence": "~1.2.2"
+  },
+  "engines": {
+    "node": ">=0.10.0"
+  },
+  "homepage": "https://github.com/request/request-promise#readme",
+  "keywords": [
+    "xhr",
+    "http",
+    "https",
+    "promise",
+    "request",
+    "then",
+    "thenable",
+    "bluebird"
+  ],
+  "license": "ISC",
+  "main": "./lib/rp.js",
+  "name": "request-promise",
+  "peerDependencies": {
+    "request": "^2.34",
+    "canvas": "^2.5.0"
+  },
+  "peerDependenciesMeta": {
+    "canvas": {
+      "optional": true
+    }
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/request/request-promise.git"
+  },
+  "scripts": {
+    "prepublish": "publish-please guard",
+    "publish-please": "publish-please",
+    "test": "gulp ci",
+    "test-publish": "gulp ci-no-cov"
+  },
+  "version": "4.2.1"
+}