fix(docker): Force npm@5 in docker builds. (#6143) r=@vladikoff

Dockerfile-build

@@ -15,6 +15,9 @@ COPY npm-shrinkwrap.json npm-shrinkwrap.json
 COPY package.json package.json
 COPY scripts/download_l10n.sh scripts/download_l10n.sh
 
+# node@6 uses npm@3 by default, which resolves dependencies incorrectly
+RUN npm install -g npm@5
+
 RUN npm install --production --unsafe-perm && rm -rf ~/.cache ~/.npm /tmp/*
 
 COPY . /app

server/bin/fxa-content-server.js

@@ -31,6 +31,16 @@ const serveStatic = require('serve-static');
 const config = require('../lib/configuration');
 const raven = require('../lib/raven');
 
+const userAgent = require('../lib/user-agent');
+if (! userAgent.isToVersionStringSupported()) {
+  // npm@3 installs the incorrect version of node-uap, one without `toVersionString`.
+  // To ensure the correct version is installed, check toVersionString is available.
+  logger.critical('dependency.version.error', {
+    error: 'node-uap does not support toVersionString()'
+  });
+  process.exit(1);
+}
+
 // This can't possibly be best way to librar-ify this module.
 const isMain = process.argv[1] === __filename;
 if (isMain) {

server/lib/user-agent.js

@@ -27,6 +27,22 @@ exports.parse = userAgentString => {
   return result;
 };
 
+exports.isToVersionStringSupported = (result) => {
+  if (! result) {
+    result = exports.parse('Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:59.0) Gecko/20100101 Firefox/59.0');
+  }
+  if (! result || ! result.os || ! result.ua) {
+    return false;
+  }
+  if (typeof result.os.toVersionString !== 'function') {
+    return false;
+  }
+  if (typeof result.ua.toVersionString !== 'function') {
+    return false;
+  }
+  return true;
+};
+
 function safeFamily (parent) {
   if (! VALID_FAMILY.test(parent.family)) {
     parent.family = null;

tests/server/user-agent.js

@@ -15,6 +15,50 @@ registerSuite('userAgent', {
     'interface is correct': () => {
       assert.isFunction(userAgent.parse);
       assert.lengthOf(userAgent.parse, 1);
+      assert.isFunction(userAgent.isToVersionStringSupported);
+    },
+
+    'isToVersionStringSupported returns false if os.toVersionString is not available': () => {
+      assert.isFalse(userAgent.isToVersionStringSupported({
+        os: {
+          major: 1,
+          minor: 0,
+        },
+        ua: {
+          major: 1,
+          minor: 0,
+          toVersionString: function () {}
+        }
+      }));
+    },
+
+    'isToVersionStringSupported returns false if ua.toVersionString is not available': () => {
+      assert.isFalse(userAgent.isToVersionStringSupported({
+        os: {
+          major: 1,
+          minor: 0,
+          toVersionString: function () {}
+        },
+        ua: {
+          major: 1,
+          minor: 0,
+        }
+      }));
+    },
+
+    'isToVersionStringSupported returns true if toVersionString is available': () => {
+      assert.isTrue(userAgent.isToVersionStringSupported({
+        os: {
+          major: 1,
+          minor: 0,
+          toVersionString: function () {}
+        },
+        ua: {
+          major: 1,
+          minor: 0,
+          toVersionString: function () {}
+        }
+      }));
     },
 
     'parses a valid user-agent string': () => {