feat(jsii): enforce peer dependencies

packages/jsii-calc-base/package.json

@@ -34,6 +34,9 @@
   "dependencies": {
     "@scope/jsii-calc-base-of-base": "^0.7.8"
   },
+  "peerDependencies": {
+    "@scope/jsii-calc-base-of-base": "^0.7.8"
+  },
   "author": {
     "name": "Amazon Web Services",
     "url": "https://aws.amazon.com",

packages/jsii-calc-base/test/assembly.jsii

@@ -9,6 +9,7 @@
   },
   "dependencies": {
     "@scope/jsii-calc-base-of-base": {
+      "peer": true,
       "targets": {
         "dotnet": {
           "namespace": "Amazon.JSII.Tests.CalculatorNamespace.BaseOfBaseNamespace",
@@ -102,5 +103,5 @@
     }
   },
   "version": "0.7.8",
-  "fingerprint": "G+ZeFV6LQWFdp9ZuDgqN4rS10q/JBHuy0Wo8qaTK/t8="
+  "fingerprint": "K1rAUs6WiQ5lF08T46B8v/5UL8T8Ot59e0Nc8rh2jiQ="
 }

packages/jsii-calc-lib/package.json

@@ -34,6 +34,9 @@
   "dependencies": {
     "@scope/jsii-calc-base": "^0.7.8"
   },
+  "peerDependencies": {
+    "@scope/jsii-calc-base": "^0.7.8"
+  },
   "author": {
     "name": "Amazon Web Services",
     "url": "https://aws.amazon.com",

packages/jsii-calc-lib/test/assembly.jsii

@@ -11,6 +11,7 @@
     "@scope/jsii-calc-base": {
       "dependencies": {
         "@scope/jsii-calc-base-of-base": {
+          "peer": true,
           "targets": {
             "dotnet": {
               "namespace": "Amazon.JSII.Tests.CalculatorNamespace.BaseOfBaseNamespace",
@@ -30,6 +31,7 @@
           "version": "0.7.8"
         }
       },
+      "peer": true,
       "targets": {
         "dotnet": {
           "namespace": "Amazon.JSII.Tests.CalculatorNamespace.BaseNamespace",
@@ -351,5 +353,5 @@
     }
   },
   "version": "0.7.8",
-  "fingerprint": "HzcyHys0b9gFmP4dogeIJmGE6GVtrSo/P0S54Vd/X8U="
+  "fingerprint": "ENH00UDSeTnXKpvD3/vp0k8zyd+KCHzc9QWB151/gM8="
 }

packages/jsii-calc/package.json

@@ -35,6 +35,10 @@
     "@scope/jsii-calc-lib": "^0.7.8",
     "jsii-calc-bundled": "^0.7.8"
   },
+  "peerDependencies": {
+    "@scope/jsii-calc-base": "^0.7.8",
+    "@scope/jsii-calc-lib": "^0.7.8"
+  },
   "devDependencies": {
     "@types/node": "^8.10.37",
     "jsii": "^0.7.8",

packages/jsii-calc/test/assembly.jsii

@@ -37,6 +37,7 @@
     "@scope/jsii-calc-base": {
       "dependencies": {
         "@scope/jsii-calc-base-of-base": {
+          "peer": true,
           "targets": {
             "dotnet": {
               "namespace": "Amazon.JSII.Tests.CalculatorNamespace.BaseOfBaseNamespace",
@@ -56,6 +57,7 @@
           "version": "0.7.8"
         }
       },
+      "peer": true,
       "targets": {
         "dotnet": {
           "namespace": "Amazon.JSII.Tests.CalculatorNamespace.BaseNamespace",
@@ -79,6 +81,7 @@
         "@scope/jsii-calc-base": {
           "dependencies": {
             "@scope/jsii-calc-base-of-base": {
+              "peer": true,
               "targets": {
                 "dotnet": {
                   "namespace": "Amazon.JSII.Tests.CalculatorNamespace.BaseOfBaseNamespace",
@@ -98,6 +101,7 @@
               "version": "0.7.8"
             }
           },
+          "peer": true,
           "targets": {
             "dotnet": {
               "namespace": "Amazon.JSII.Tests.CalculatorNamespace.BaseNamespace",
@@ -117,6 +121,7 @@
           "version": "0.7.8"
         }
       },
+      "peer": true,
       "targets": {
         "dotnet": {
           "namespace": "Amazon.JSII.Tests.CalculatorNamespace.LibNamespace",
@@ -3407,5 +3412,5 @@
     }
   },
   "version": "0.7.8",
-  "fingerprint": "jHSXTzCSZbwYMvLKpeZB6SE8hNgYgt9/2JF1ihM41SI="
+  "fingerprint": "Xn7Rk17rqR3AaMx3+ssxT0GR1sCWwz0OGC+C8QuLI3A="
 }

packages/jsii-pacmak/test/expected.jsii-calc-base/dotnet/Amazon.JSII.Tests.CalculatorPackageId.BasePackageId/.jsii

@@ -9,6 +9,7 @@
   },
   "dependencies": {
     "@scope/jsii-calc-base-of-base": {
+      "peer": true,
       "targets": {
         "dotnet": {
           "namespace": "Amazon.JSII.Tests.CalculatorNamespace.BaseOfBaseNamespace",
@@ -102,5 +103,5 @@
     }
   },
   "version": "0.7.8",
-  "fingerprint": "G+ZeFV6LQWFdp9ZuDgqN4rS10q/JBHuy0Wo8qaTK/t8="
+  "fingerprint": "K1rAUs6WiQ5lF08T46B8v/5UL8T8Ot59e0Nc8rh2jiQ="
 }

packages/jsii-pacmak/test/expected.jsii-calc-lib/dotnet/Amazon.JSII.Tests.CalculatorPackageId.LibPackageId/.jsii

@@ -11,6 +11,7 @@
     "@scope/jsii-calc-base": {
       "dependencies": {
         "@scope/jsii-calc-base-of-base": {
+          "peer": true,
           "targets": {
             "dotnet": {
               "namespace": "Amazon.JSII.Tests.CalculatorNamespace.BaseOfBaseNamespace",
@@ -30,6 +31,7 @@
           "version": "0.7.8"
         }
       },
+      "peer": true,
       "targets": {
         "dotnet": {
           "namespace": "Amazon.JSII.Tests.CalculatorNamespace.BaseNamespace",
@@ -351,5 +353,5 @@
     }
   },
   "version": "0.7.8",
-  "fingerprint": "HzcyHys0b9gFmP4dogeIJmGE6GVtrSo/P0S54Vd/X8U="
+  "fingerprint": "ENH00UDSeTnXKpvD3/vp0k8zyd+KCHzc9QWB151/gM8="
 }

packages/jsii-pacmak/test/expected.jsii-calc/dotnet/Amazon.JSII.Tests.CalculatorPackageId/.jsii

@@ -37,6 +37,7 @@
     "@scope/jsii-calc-base": {
       "dependencies": {
         "@scope/jsii-calc-base-of-base": {
+          "peer": true,
           "targets": {
             "dotnet": {
               "namespace": "Amazon.JSII.Tests.CalculatorNamespace.BaseOfBaseNamespace",
@@ -56,6 +57,7 @@
           "version": "0.7.8"
         }
       },
+      "peer": true,
       "targets": {
         "dotnet": {
           "namespace": "Amazon.JSII.Tests.CalculatorNamespace.BaseNamespace",
@@ -79,6 +81,7 @@
         "@scope/jsii-calc-base": {
           "dependencies": {
             "@scope/jsii-calc-base-of-base": {
+              "peer": true,
               "targets": {
                 "dotnet": {
                   "namespace": "Amazon.JSII.Tests.CalculatorNamespace.BaseOfBaseNamespace",
@@ -98,6 +101,7 @@
               "version": "0.7.8"
             }
           },
+          "peer": true,
           "targets": {
             "dotnet": {
               "namespace": "Amazon.JSII.Tests.CalculatorNamespace.BaseNamespace",
@@ -117,6 +121,7 @@
           "version": "0.7.8"
         }
       },
+      "peer": true,
       "targets": {
         "dotnet": {
           "namespace": "Amazon.JSII.Tests.CalculatorNamespace.LibNamespace",
@@ -3407,5 +3412,5 @@
     }
   },
   "version": "0.7.8",
-  "fingerprint": "jHSXTzCSZbwYMvLKpeZB6SE8hNgYgt9/2JF1ihM41SI="
+  "fingerprint": "Xn7Rk17rqR3AaMx3+ssxT0GR1sCWwz0OGC+C8QuLI3A="
 }

packages/jsii-spec/lib/spec.ts

@@ -153,6 +153,22 @@ export interface PackageVersion {
 
     /** Dependencies of this dependency */
     dependencies?: { [assembly: string]: PackageVersion };
+
+    /**
+     * Indicates if this dependency is a peer dependency or a normal dependency.
+     *
+     * Peer dependencies are expected to be explicitly defined by the user of
+     * this library instead of brought in as transitive dependencies.
+     *
+     * jsii enforces that if this module exports a type from a dependency, this
+     * dependency must be defined as a peer and not as a normal dependency.
+     * Otherwise, it would be impossible to safely use two versions of this
+     * dependency in a closure.
+     *
+     * @see https://github.com/awslabs/aws-cdk/issues/979
+     * @see https://nodejs.org/en/blog/npm/peer-dependencies/
+     */
+    peer?: boolean;
 }
 
 /**

packages/jsii/bin/jsii-fix-peers

@@ -0,0 +1,2 @@
+#!/usr/bin/env node
+require('./jsii-fix-peers.js');

packages/jsii/bin/jsii-fix-peers.ts

@@ -0,0 +1,95 @@
+//
+// jsii-fix-peers
+//
+// Inspects the local .jsii file and adds "peerDependencies" to the local
+// package.json for all modules that include types that are referenced as part
+// of the current module's public API.
+//
+// This resolves all peer dependency warnings emitted by the jsii compiler.
+//
+
+// tslint:disable:no-console
+
+import fs = require('fs-extra');
+import spec = require('jsii-spec');
+
+fixPeers().catch(e => {
+  console.error(e.stack);
+  process.exit(1);
+});
+
+async function fixPeers() {
+  const jsiiFile = './.jsii';
+  const pkgFile = './package.json';
+
+  if (!(await fs.pathExists(jsiiFile))) {
+    throw new Error(`Cannot find '${jsiiFile}. Make sure to compile first`);
+  }
+
+  if (!(await fs.pathExists(pkgFile))) {
+    throw new Error(`Cannot find '${pkgFile}' in current working directory`);
+  }
+
+  const jsii = await fs.readJson(jsiiFile) as spec.Assembly;
+  const pkg = await fs.readJson(pkgFile);
+
+  // find all type references (FQNs) in the assembly.
+  const fqns = findAllFQNs(jsii);
+
+  let updated = false;
+
+  // read "dependencies" and "peerDependencies" from package.json
+  if (!pkg.peerDependencies) { pkg.peerDependencies = {}; }
+  const peers = pkg.peerDependencies;
+  const deps = pkg.dependencies || {};
+
+  // iterate over all FQNs and ensure that all referenced modules appear as peer dependencies
+  for (const fqn of fqns) {
+    const [ module, ] = fqn.split('.');
+    if (module === jsii.name) {
+      continue;
+    }
+
+    // verify that `module` exists in peerDependencies
+    if (module in peers) {
+      continue;
+    }
+
+    // fetch the module's version requirement from "dependencies" (we expect it to be there)
+    const dep = deps[module];
+    if (!dep) {
+      throw new Error(`Cannot find ${module} neither under "peerDependencies" nor "dependencies". Can't fix.`);
+    }
+
+    // fixing time! add this module to "peerDependencies"
+    peers[module] = dep;
+    console.log(`added ${module}@${dep} to "peerDependencies"`);
+    updated = true;
+  }
+
+  if (updated) {
+    await fs.writeJson(pkgFile, pkg, { spaces: 2 });
+  }
+}
+
+/**
+ * Looks up all { "fqn": "boom" } objects in a JSON tree.
+ * @param node Initial node (i.e. a JSII assembly)
+ * @param out Used by the recursive call to collect outputs
+ */
+function findAllFQNs(node: any, out = new Set<string>()) {
+  if (typeof(node) === 'object' && 'fqn' in node) {
+    out.add(node.fqn);
+  }
+
+  for (const key of Object.keys(node)) {
+    const value = node[key];
+    if (Array.isArray(value)) {
+      value.forEach(v => findAllFQNs(v, out));
+    } else if (typeof(value) === 'object') {
+      findAllFQNs(value, out);
+    }
+  }
+
+  return Array.from(out);
+}