fix: add deprecation notice for node versions 6 and 8 (#32)

* fix: add deprecation notice for node versions 6 and 8 in both readme and base service
* ci: disable caching in travis

.travis.yml

@@ -1,9 +1,10 @@
 language: node_js
 sudo: false
 node_js:
-- 6
-- 8
 - 10
+- 12
+cache:
+  npm: false
 script:
 - npm run prepare
 - npm run lint
@@ -17,4 +18,5 @@ deploy:
   skip_cleanup: true
   script: npx semantic-release
   on:
-    node: 10
+    node: 12
+    repo: IBM/node-sdk-core

README.md

@@ -7,6 +7,9 @@
 This project contains the core functionality used by Node SDK's generated by the IBM OpenAPI 3 SDK Generator (`openapi-sdkgen`).
 Code generated by `openapi-sdkgen` will depend on the functionality contained in this project.
 
+## Notice
+Support for Node versions **6** and **8** is deprecated and will be officially dropped in the next major release, which is expected to be in September, 2019. Version 6 reached end of life in April 2019 and Version 8 reaches end of life on 31 December 2019.
+
 ## Installation
 `npm install ibm-cloud-sdk-core`
 

lib/base_service.ts

@@ -15,6 +15,7 @@
  */
 
 import extend = require('extend');
+import semver = require('semver');
 import vcapServices = require('vcap_services');
 import { computeBasicAuthHeader, IamTokenManagerV1, Icp4dTokenManagerV1 } from '../auth';
 import { stripTrailingSlash } from './helper';
@@ -165,6 +166,18 @@ export class BaseService {
         'the "new" keyword is required to create Watson service instances'
       );
     }
+
+    // deprecate node versions 6 and 8
+    // these will be removed in v5
+    const isNodeSix = semver.satisfies(process.version, '6.x');
+    const isNodeEight = semver.satisfies(process.version, '8.x');
+    if (isNodeSix) {
+      console.warn('Node v6 will not be supported in the SDK in the next major release (09/2019). Version 6 reached end of life in April 2019.');
+    }
+    if (isNodeEight) {
+      console.warn('Node v8 will not be supported in the SDK in the next major release (09/2019). Version 8 reaches end of life on 31 December 2019.');
+    }
+
     const options = extend({}, userOptions);
 
     const _options = this.initCredentials(options);

package.json

@@ -65,6 +65,7 @@
     "mime-types": "~2.1.18",
     "object.omit": "~3.0.0",
     "object.pick": "~1.3.0",
+    "semver": "^6.2.0",
     "vcap_services": "~0.3.4"
   },
   "engines": {