diff --git a/tap-snapshots/test-lib-config.js-TAP.test.js b/tap-snapshots/test-lib-config.js-TAP.test.js
new file mode 100644
index 0000000000000..1794dc4fadfb8
--- /dev/null
+++ b/tap-snapshots/test-lib-config.js-TAP.test.js
@@ -0,0 +1,150 @@
+/* IMPORTANT
+ * This snapshot file is auto-generated, but designed for humans.
+ * It should be checked into source control and tracked carefully.
+ * Re-generate by setting TAP_SNAPSHOT=1 and running tests.
+ * Make sure to inspect the output below.  Do not ignore changes!
+ */
+'use strict'
+exports[`test/lib/config.js TAP config edit --global > should write global config file 1`] = `
+;;;;
+; npm globalconfig file: /etc/npmrc
+; this is a simple ini-formatted file
+; lines that start with semi-colons are comments
+; run \`npm help 7 config\` for documentation of the various options
+;
+; Configs like \`@scope:registry\` map a scope to a given registry url.
+;
+; Configs like \`//<hostname>/:_authToken\` are auth that is restricted
+; to the registry host specified.
+
+init.author.name=Foo
+
+;;;;
+; all available options shown below with default values
+;;;;
+
+
+; init-author-name=
+; init-version=1.0.0
+; init.author.name=
+; init.version=1.0.0
+
+`
+
+exports[`test/lib/config.js TAP config edit > should write config file 1`] = `
+;;;;
+; npm userconfig file: ~/.npmrc
+; this is a simple ini-formatted file
+; lines that start with semi-colons are comments
+; run \`npm help 7 config\` for documentation of the various options
+;
+; Configs like \`@scope:registry\` map a scope to a given registry url.
+;
+; Configs like \`//<hostname>/:_authToken\` are auth that is restricted
+; to the registry host specified.
+
+//registry.npmjs.org/:_authToken=0000000
+init.author.name=Foo
+sign-git-commit=true
+
+;;;;
+; all available options shown below with default values
+;;;;
+
+
+; init-author-name=
+; init-version=1.0.0
+; init.author.name=
+; init.version=1.0.0
+
+`
+
+exports[`test/lib/config.js TAP config edit > should write config file 2`] = `
+;;;;
+; npm userconfig file: ~/.npmrc
+; this is a simple ini-formatted file
+; lines that start with semi-colons are comments
+; run \`npm help 7 config\` for documentation of the various options
+;
+; Configs like \`@scope:registry\` map a scope to a given registry url.
+;
+; Configs like \`//<hostname>/:_authToken\` are auth that is restricted
+; to the registry host specified.
+
+
+
+;;;;
+; all available options shown below with default values
+;;;;
+
+
+; init-author-name=
+; init-version=1.0.0
+; init.author.name=
+; init.version=1.0.0
+
+`
+
+exports[`test/lib/config.js TAP config get no args > should list configs on config get no args 1`] = `
+; "cli" config from command line options
+
+editor = "vi" 
+global = false 
+json = false 
+long = false 
+
+; node bin location = /path/to/node
+; cwd = {CWD}
+; HOME = ~/
+; Run \`npm config ls -l\` to show all defaults.
+`
+
+exports[`test/lib/config.js TAP config list --long > should list all configs 1`] = `
+; "default" config from default values
+
+init-author-name = "" 
+init-version = "1.0.0" 
+init.author.name = "" 
+init.version = "1.0.0" 
+
+; "cli" config from command line options
+
+editor = "vi" 
+global = false 
+json = false 
+long = true
+`
+
+exports[`test/lib/config.js TAP config list > should list configs 1`] = `
+; "cli" config from command line options
+
+editor = "vi" 
+global = false 
+json = false 
+long = false 
+
+; node bin location = /path/to/node
+; cwd = {CWD}
+; HOME = ~/
+; Run \`npm config ls -l\` to show all defaults.
+`
+
+exports[`test/lib/config.js TAP config list overrides > should list overriden configs 1`] = `
+; "cli" config from command line options
+
+editor = "vi" 
+global = false 
+init.author.name = "Bar" 
+json = false 
+long = false 
+
+; "user" config from ~/.npmrc
+
+; //private-reg.npmjs.org/:_authThoken = (protected) ; overridden by cli
+; init.author.name = "Foo" ; overridden by cli
+
+; node bin location = /path/to/node
+; cwd = {CWD}
+; HOME = ~/
+; Run \`npm config ls -l\` to show all defaults.
+`
diff --git a/test/lib/config.js b/test/lib/config.js
new file mode 100644
index 0000000000000..d94af00cb1a00
--- /dev/null
+++ b/test/lib/config.js
@@ -0,0 +1,578 @@
+const t = require('tap')
+const requireInject = require('require-inject')
+
+const redactCwd = (path) => {
+  const normalizePath = p => p
+    .replace(/\\+/g, '/')
+    .replace(/\r\n/g, '\n')
+  return normalizePath(path)
+    .replace(new RegExp(normalizePath(process.cwd()), 'g'), '{CWD}')
+    .replace(process.execPath, '/path/to/node')
+    .replace(process.env.HOME, '~/')
+}
+
+t.cleanSnapshot = (str) => redactCwd(str)
+
+let result = ''
+const types = {
+  'init-author-name': String,
+  'init-version': String,
+  'init.author.name': String,
+  'init.version': String
+}
+const defaults = {
+  'init-author-name': '',
+  'init-version': '1.0.0',
+  'init.author.name': '',
+  'init.version': '1.0.0'
+}
+
+const flatOptions = {
+  editor: 'vi',
+  json: false,
+  long: false,
+  global: false
+}
+
+const npm = {
+  flatOptions,
+  log: {
+    info: () => null,
+    enableProgress: () => null,
+    disableProgress: () => null
+  },
+  config: {
+    data: new Map(Object.entries({
+      default: { data: defaults, source: 'default values' },
+      global: { data: {}, source: '/etc/npmrc' },
+      cli: { data: flatOptions, source: 'command line options' }
+    })),
+    get (key) { return flatOptions[key] },
+    validate () { return true }
+  }
+}
+
+const usageUtil = () => 'usage instructions'
+
+const mocks = {
+  '../../lib/utils/config.js': { defaults, types },
+  '../../lib/npm.js': npm,
+  '../../lib/utils/output.js': msg => { result = msg },
+  '../../lib/utils/usage.js': usageUtil
+}
+
+const config = requireInject('../../lib/config.js', mocks)
+
+t.test('config no args', t => {
+  config([], (err) => {
+    t.match(err, /usage instructions/, 'should not error out on empty locations')
+    t.end()
+  })
+})
+
+t.test('config list', t => {
+  t.plan(2)
+
+  npm.config.find = () => 'cli'
+  result = ''
+  t.teardown(() => {
+    result = ''
+    delete npm.config.find
+  })
+
+  config(['list'], (err) => {
+    t.ifError(err, 'npm config list')
+    t.matchSnapshot(result, 'should list configs')
+  })
+})
+
+t.test('config list overrides', t => {
+  t.plan(2)
+
+  npm.config.data.set('user', {
+    data: {
+      'init.author.name': 'Foo',
+      '//private-reg.npmjs.org/:_authThoken': 'f00ba1'
+    },
+    source: '~/.npmrc'
+  })
+  flatOptions['init.author.name'] = 'Bar'
+  npm.config.find = () => 'cli'
+  result = ''
+  t.teardown(() => {
+    result = ''
+    npm.config.data.delete('user')
+    delete flatOptions['init.author.name']
+    delete npm.config.find
+  })
+
+  config(['list'], (err) => {
+    t.ifError(err, 'npm config list')
+    t.matchSnapshot(result, 'should list overriden configs')
+  })
+})
+
+t.test('config list --long', t => {
+  t.plan(2)
+
+  npm.config.find = key => key in flatOptions ? 'cli' : 'default'
+  flatOptions.long = true
+  result = ''
+  t.teardown(() => {
+    delete npm.config.find
+    flatOptions.long = false
+    result = ''
+  })
+
+  config(['list'], (err) => {
+    t.ifError(err, 'npm config list --long')
+    t.matchSnapshot(result, 'should list all configs')
+  })
+})
+
+t.test('config list --json', t => {
+  t.plan(2)
+
+  flatOptions.json = true
+  result = ''
+  npm.config.list = [{
+    '//private-reg.npmjs.org/:_authThoken': 'f00ba1',
+    ...npm.config.data.get('cli').data
+  }]
+  const npmConfigGet = npm.config.get
+  npm.config.get = key => npm.config.list[0][key]
+
+  t.teardown(() => {
+    delete npm.config.list
+    flatOptions.json = false
+    npm.config.get = npmConfigGet
+    result = ''
+  })
+
+  config(['list'], (err) => {
+    t.ifError(err, 'npm config list --json')
+    t.deepEqual(
+      JSON.parse(result),
+      {
+        editor: 'vi',
+        json: true,
+        long: false,
+        global: false
+      },
+      'should list configs usin json'
+    )
+  })
+})
+
+t.test('config delete no args', t => {
+  config(['delete'], (err) => {
+    t.equal(
+      err,
+      'usage instructions',
+      'should throw usage error'
+    )
+    t.end()
+  })
+})
+
+t.test('config delete key', t => {
+  t.plan(4)
+
+  npm.config.delete = (key, where) => {
+    t.equal(key, 'foo', 'should delete expected keyword')
+    t.equal(where, 'user', 'should delete key from user config by default')
+  }
+
+  npm.config.save = where => {
+    t.equal(where, 'user', 'should save user config post-delete')
+  }
+
+  config(['delete', 'foo'], (err) => {
+    t.ifError(err, 'npm config delete key')
+  })
+
+  t.teardown(() => {
+    delete npm.config.delete
+    delete npm.config.save
+  })
+})
+
+t.test('config delete key --global', t => {
+  t.plan(4)
+
+  npm.config.delete = (key, where) => {
+    t.equal(key, 'foo', 'should delete expected keyword from global configs')
+    t.equal(where, 'global', 'should delete key from global config by default')
+  }
+
+  npm.config.save = where => {
+    t.equal(where, 'global', 'should save global config post-delete')
+  }
+
+  flatOptions.global = true
+  config(['delete', 'foo'], (err) => {
+    t.ifError(err, 'npm config delete key --global')
+  })
+
+  t.teardown(() => {
+    flatOptions.global = false
+    delete npm.config.delete
+    delete npm.config.save
+  })
+})
+
+t.test('config set no args', t => {
+  config(['set'], (err) => {
+    t.equal(
+      err,
+      'usage instructions',
+      'should throw usage error'
+    )
+    t.end()
+  })
+})
+
+t.test('config set key', t => {
+  t.plan(5)
+
+  npm.config.set = (key, val, where) => {
+    t.equal(key, 'foo', 'should set expected key to user config')
+    t.equal(val, 'bar', 'should set expected value to user config')
+    t.equal(where, 'user', 'should set key/val in user config by default')
+  }
+
+  npm.config.save = where => {
+    t.equal(where, 'user', 'should save user config')
+  }
+
+  config(['set', 'foo', 'bar'], (err) => {
+    t.ifError(err, 'npm config set key')
+  })
+
+  t.teardown(() => {
+    delete npm.config.set
+    delete npm.config.save
+  })
+})
+
+t.test('config set key=val', t => {
+  t.plan(5)
+
+  npm.config.set = (key, val, where) => {
+    t.equal(key, 'foo', 'should set expected key to user config')
+    t.equal(val, 'bar', 'should set expected value to user config')
+    t.equal(where, 'user', 'should set key/val in user config by default')
+  }
+
+  npm.config.save = where => {
+    t.equal(where, 'user', 'should save user config')
+  }
+
+  config(['set', 'foo=bar'], (err) => {
+    t.ifError(err, 'npm config set key')
+  })
+
+  t.teardown(() => {
+    delete npm.config.set
+    delete npm.config.save
+  })
+})
+
+t.test('config set key to empty value', t => {
+  t.plan(5)
+
+  npm.config.set = (key, val, where) => {
+    t.equal(key, 'foo', 'should set expected key to user config')
+    t.equal(val, '', 'should set empty value to user config')
+    t.equal(where, 'user', 'should set key/val in user config by default')
+  }
+
+  npm.config.save = where => {
+    t.equal(where, 'user', 'should save user config')
+  }
+
+  config(['set', 'foo'], (err) => {
+    t.ifError(err, 'npm config set key to empty value')
+  })
+
+  t.teardown(() => {
+    delete npm.config.set
+    delete npm.config.save
+  })
+})
+
+t.test('config set invalid key', t => {
+  t.plan(3)
+
+  const npmConfigValidate = npm.config.validate
+  npm.config.save = () => null
+  npm.config.set = () => null
+  npm.config.validate = () => false
+  npm.log.warn = (title, msg) => {
+    t.equal(title, 'config', 'should warn with expected title')
+    t.equal(msg, 'omitting invalid config values', 'should use expected msg')
+  }
+  t.teardown(() => {
+    npm.config.validate = npmConfigValidate
+    delete npm.config.save
+    delete npm.config.set
+    delete npm.log.warn
+  })
+
+  config(['set', 'foo', 'bar'], (err) => {
+    t.ifError(err, 'npm config set invalid key')
+  })
+})
+
+t.test('config set key --global', t => {
+  t.plan(5)
+
+  npm.config.set = (key, val, where) => {
+    t.equal(key, 'foo', 'should set expected key to global config')
+    t.equal(val, 'bar', 'should set expected value to global config')
+    t.equal(where, 'global', 'should set key/val in global config')
+  }
+
+  npm.config.save = where => {
+    t.equal(where, 'global', 'should save global config')
+  }
+
+  flatOptions.global = true
+  config(['set', 'foo', 'bar'], (err) => {
+    t.ifError(err, 'npm config set key --global')
+  })
+
+  t.teardown(() => {
+    flatOptions.global = false
+    delete npm.config.set
+    delete npm.config.save
+  })
+})
+
+t.test('config get no args', t => {
+  t.plan(2)
+
+  npm.config.find = () => 'cli'
+  result = ''
+  t.teardown(() => {
+    result = ''
+    delete npm.config.find
+  })
+
+  config(['get'], (err) => {
+    t.ifError(err, 'npm config get no args')
+    t.matchSnapshot(result, 'should list configs on config get no args')
+  })
+})
+
+t.test('config get key', t => {
+  t.plan(3)
+
+  const npmConfigGet = npm.config.get
+  npm.config.get = (key, where) => {
+    t.equal(key, 'foo', 'should use expected key')
+    t.equal(where, 'user', 'should retrieve key from user config by default')
+    return 'bar'
+  }
+
+  npm.config.save = where => {
+    throw new Error('should not save')
+  }
+
+  config(['get', 'foo'], (err) => {
+    t.ifError(err, 'npm config get key')
+  })
+
+  t.teardown(() => {
+    npm.config.get = npmConfigGet
+    delete npm.config.save
+  })
+})
+
+t.test('config get key --global', t => {
+  t.plan(3)
+
+  flatOptions.global = true
+  const npmConfigGet = npm.config.get
+  npm.config.get = (key, where) => {
+    t.equal(key, 'foo', 'should use expected global key')
+    t.equal(where, 'global', 'should retrieve key from global config')
+    return 'bar'
+  }
+
+  npm.config.save = where => {
+    throw new Error('should not save')
+  }
+
+  config(['get', 'foo'], (err) => {
+    t.ifError(err, 'npm config get key --global')
+  })
+
+  t.teardown(() => {
+    flatOptions.global = false
+    npm.config.get = npmConfigGet
+    delete npm.config.save
+  })
+})
+
+t.test('config get private key', t => {
+  config(['get', '//private-reg.npmjs.org/:_authThoken'], (err) => {
+    t.match(
+      err,
+      /The \/\/private-reg.npmjs.org\/:_authThoken option is protected, and cannot be retrieved in this way/,
+      'should throw unable to retrieve error'
+    )
+    t.end()
+  })
+})
+
+t.test('config edit', t => {
+  t.plan(12)
+  const npmrc = `//registry.npmjs.org/:_authToken=0000000
+init.author.name=Foo
+sign-git-commit=true`
+  npm.config.data.set('user', {
+    source: '~/.npmrc'
+  })
+  npm.config.save = async where => {
+    t.equal(where, 'user', 'should save to user config by default')
+  }
+  const editMocks = {
+    ...mocks,
+    'mkdirp-infer-owner': async () => null,
+    fs: {
+      readFile (path, encoding, cb) { cb(null, npmrc) },
+      writeFile (file, data, encoding, cb) {
+        t.equal(file, '~/.npmrc', 'should save to expected file location')
+        t.matchSnapshot(data, 'should write config file')
+        cb()
+      }
+    },
+    editor: (file, { editor }, cb) => {
+      t.equal(file, '~/.npmrc', 'should match user source data')
+      t.equal(editor, 'vi', 'should use default editor')
+      cb()
+    }
+  }
+  const config = requireInject('../../lib/config.js', editMocks)
+  config(['edit'], (err) => {
+    t.ifError(err, 'npm config edit')
+
+    // test no config file result
+    editMocks.fs.readFile = (p, e, cb) => { cb(new Error('ERR')) }
+    const config = requireInject('../../lib/config.js', editMocks)
+    config(['edit'], (err) => {
+      t.ifError(err, 'npm config edit')
+    })
+  })
+
+  t.teardown(() => {
+    npm.config.data.delete('user')
+    delete npm.config.save
+  })
+})
+
+t.test('config edit --global', t => {
+  t.plan(6)
+
+  flatOptions.global = true
+  const npmrc = 'init.author.name=Foo'
+  npm.config.data.set('global', {
+    source: '/etc/npmrc'
+  })
+  npm.config.save = async where => {
+    t.equal(where, 'global', 'should save to global config')
+  }
+  const editMocks = {
+    ...mocks,
+    'mkdirp-infer-owner': async () => null,
+    fs: {
+      readFile (path, encoding, cb) { cb(null, npmrc) },
+      writeFile (file, data, encoding, cb) {
+        t.equal(file, '/etc/npmrc', 'should save to global file location')
+        t.matchSnapshot(data, 'should write global config file')
+        cb()
+      }
+    },
+    editor: (file, { editor }, cb) => {
+      t.equal(file, '/etc/npmrc', 'should match global source data')
+      t.equal(editor, 'vi', 'should use default editor')
+      cb()
+    }
+  }
+  const config = requireInject('../../lib/config.js', editMocks)
+  config(['edit'], (err) => {
+    t.ifError(err, 'npm config edit --global')
+  })
+
+  t.teardown(() => {
+    flatOptions.global = false
+    npm.config.data.delete('user')
+    delete npm.config.save
+  })
+})
+
+t.test('config edit no editor set', t => {
+  flatOptions.editor = undefined
+  config(['edit'], (err) => {
+    t.match(
+      err,
+      /No `editor` config or EDITOR environment variable set/,
+      'should throw no available editor error'
+    )
+    flatOptions.editor = 'vi'
+    t.end()
+  })
+})
+
+t.test('completion', t => {
+  const { completion } = config
+
+  const testComp = (argv, expect) => {
+    completion({ conf: { argv: { remain: argv } } }, (er, res) => {
+      t.ifError(er)
+      t.strictSame(res, expect, argv.join(' '))
+    })
+  }
+
+  testComp(['npm', 'foo'], [])
+  testComp(['npm', 'config'], [
+    'get',
+    'set',
+    'delete',
+    'ls',
+    'rm',
+    'edit',
+    'list'
+  ])
+  testComp(['npm', 'config', 'set', 'foo'], [])
+  const possibleConfigKeys = [...Object.keys(types)]
+  testComp(['npm', 'config', 'get'], possibleConfigKeys)
+  testComp(['npm', 'config', 'set'], possibleConfigKeys)
+  testComp(['npm', 'config', 'delete'], possibleConfigKeys)
+  testComp(['npm', 'config', 'rm'], possibleConfigKeys)
+  testComp(['npm', 'config', 'edit'], [])
+  testComp(['npm', 'config', 'list'], [])
+  testComp(['npm', 'config', 'ls'], [])
+
+  completion({
+    conf: {
+      argv: {
+        remain: ['npm', 'config']
+      }
+    },
+    partialWord: 'l'
+  }, (er, res) => {
+    t.ifError(er)
+    t.strictSame(res, [
+      'get',
+      'set',
+      'delete',
+      'ls',
+      'rm',
+      'edit'
+    ], 'npm config')
+  })
+
+  t.end()
+})