module-name: Factor out module name reading

Bring consistent guarding against null/undefined and consistent
business logic.

PR-URL: //github.com/npm/npm/pull/9890
Fixes: #9766

2 files changed, 42 insertions, 2 deletions

diff --git a/test/tap/add-remote-git-shrinkwrap.js b/test/tap/add-remote-git-shrinkwrap.js
index f2982355e..d734c11cf 100644
--- a/test/tap/add-remote-git-shrinkwrap.js
+++ b/test/tap/add-remote-git-shrinkwrap.js
@@ -61,9 +61,9 @@ test('shrinkwrap gets correct _from and _resolved (#7121)', function (t) {
     { cwd: pkg },
     function (er, code, stdout, stderr) {
       t.ifError(er, 'npm shrinkwrapped without errors')
-      t.notOk(code, '`npm shrinkwrap` exited with 0')
+      t.is(code, 0, '`npm shrinkwrap` exited ok')
       t.equal(stdout.trim(), 'wrote npm-shrinkwrap.json')
-      t.notOk(stderr, 'no error output on successful shrinkwrap')
+      t.equal(stderr.trim(), '', 'no error output on successful shrinkwrap')
 
       var shrinkwrap = require(resolve(pkg, 'npm-shrinkwrap.json'))
       t.equal(
diff --git a/test/tap/unit-module-name.js b/test/tap/unit-module-name.js
new file mode 100644
index 000000000..59d4b44f0
--- /dev/null
+++ b/test/tap/unit-module-name.js
@@ -0,0 +1,40 @@
+'use strict'
+var test = require('tap').test
+var moduleName = require('../../lib/utils/module-name.js')
+
+test('pathToPackageName', function (t) {
+  var pathToPackageName = moduleName.test.pathToPackageName
+  t.is(pathToPackageName('/foo/bar/baz/bark'), 'bark', 'simple module name')
+  t.is(pathToPackageName('/foo/bar/@baz/bark'), '@baz/bark', 'scoped module name')
+  t.is(pathToPackageName('/foo'), 'foo', 'module at top')
+  t.is(pathToPackageName('/@foo'), '@foo', 'invalid module at top')
+  t.is(pathToPackageName('/'), '', 'root, empty result')
+  t.is(pathToPackageName(''), '', 'empty, empty')
+  t.is(pathToPackageName(undefined), '', 'undefined is empty')
+  t.is(pathToPackageName(null), '', 'null is empty')
+  t.done()
+})
+
+test('isNotEmpty', function (t) {
+  var isNotEmpty = moduleName.test.isNotEmpty
+  t.is(isNotEmpty('abc'), true, 'string is not empty')
+  t.is(isNotEmpty(''), false, 'empty string is empty')
+  t.is(isNotEmpty(null), false, 'null is empty')
+  t.is(isNotEmpty(undefined), false, 'undefined is empty')
+  t.is(isNotEmpty(0), true, 'zero is not empty')
+  t.is(isNotEmpty(true), true, 'true is not empty')
+  t.is(isNotEmpty([]), true, 'empty array is not empty')
+  t.is(isNotEmpty({}), true, 'object is not empty')
+  t.done()
+})
+
+test('moduleName', function (t) {
+  t.is(moduleName({package: {name: 'foo'}}), 'foo', 'package named')
+  t.is(moduleName({name: 'foo'}), 'foo', 'package named, no tree')
+  t.is(moduleName({path: '/foo/bar'}), 'bar', 'path named')
+  t.is(moduleName({}), '!invalid#1', 'no named')
+  t.is(moduleName({path: '/'}), '!invalid#2', 'invalid named')
+  var obj = {}
+  t.is(moduleName(obj), moduleName(obj), 'once computed, an invalid module name will not change')
+  t.done()
+})