feat: remove undefined/nulls from env

package.json

@@ -10,6 +10,7 @@
   },
   "devDependencies": {
     "@dxcli/dev": "^2.0.4",
+    "@dxcli/tslint": "^0.0.23",
     "@types/sinon": "^4.1.3",
     "chai": "^4.1.2",
     "chalk": "^2.3.0",

src/env.ts

@@ -1,11 +1,24 @@
+import * as _ from 'lodash'
+
 import {Env, EnvOptions} from './types'
 
-export default (env: {[k: string]: string | undefined}, opts: EnvOptions = {}) => ({
+export default (env: {[k: string]: string | null | undefined}, opts: EnvOptions = {}) => ({
   run(ctx) {
+    // normalize to undefined
+    const normalizedEnv = _.mapValues(env, v => v === null ? undefined : v)
+
+    // store previous env for finally
     ctx.envs = ctx.envs || []
     ctx.envs.push(process.env)
-    if (opts.clear) process.env = {...env}
-    else process.env = {...process.env, ...env}
+
+    if (opts.clear) {
+      process.env = {...normalizedEnv}
+    } else {
+      process.env = {...process.env, ...normalizedEnv}
+      Object.entries(normalizedEnv)
+      .filter(([, v]) => v === undefined)
+      .forEach(([k]) => { delete process.env[k] })
+    }
   },
   finally(ctx) {
     const env = ctx.envs.pop()

test/env.test.ts

@@ -30,6 +30,12 @@ describe('env', () => {
   fancy
   .env({PREDEFINED: undefined})
   .end('can set things to be undefined', () => {
-    expect(process.env.PREDEFINED).to.equal(undefined)
+    expect(process.env).to.not.have.property('PREDEFINED')
+  })
+
+  fancy
+  .env({PREDEFINED: null})
+  .end('can set things to be null', () => {
+    expect(process.env).to.not.have.property('PREDEFINED')
   })
 })

tslint.json

@@ -1,3 +1,3 @@
 {
-  "extends": "@dxcli/dev-tslint"
+  "extends": "@dxcli/tslint"
 }

yarn.lock

@@ -159,6 +159,13 @@
     ts-node "^4.1.0"
     typescript "^2.6.2"
 
+"@dxcli/tslint@^0.0.23":
+  version "0.0.23"
+  resolved "https://registry.yarnpkg.com/@dxcli/tslint/-/tslint-0.0.23.tgz#c9877ec9927bb958c1a71edac3263007ce64b22d"
+  dependencies:
+    tslint "^5.9.1"
+    tslint-xo "^0.5.0"
+
 "@marionebl/sander@^0.6.0":
   version "0.6.1"
   resolved "https://registry.yarnpkg.com/@marionebl/sander/-/sander-0.6.1.tgz#1958965874f24bc51be48875feb50d642fc41f7b"