fix: allow `--lockfile-version` config to be string and coerce to number

As all CLI input is considered to be string, eg. a
"npm install --lockfile-version 3" would fail with the error messages:

```
npm WARN invalid config lockfile-version="3" set in command line options
npm WARN invalid config Must be one of: null, 1, 2, 3
```

Until we have a config system that supports setting type and possible values
of configs, we have to specify all string and number values for the
`lockfile-version`, but we coerce all values to numbers in the flattener.

Co-authored-by: @voxpelli
Co-authored-by: @isaacs

PR-URL: https://github.com/npm/cli/pull/3949
Credit: @lukekarrys
Close: #3949
Reviewed-by: @isaacs

1 files changed, 9 insertions, 0 deletions

diff --git a/test/lib/utils/config/definitions.js b/test/lib/utils/config/definitions.js
index 622e603bc..15b43715f 100644
--- a/test/lib/utils/config/definitions.js
+++ b/test/lib/utils/config/definitions.js
@@ -892,3 +892,12 @@ t.test('workspaces derived', t => {
   t.equal(flat.workspacesEnabled, false)
   t.end()
 })
+
+t.test('lockfile version', t => {
+  const flat = {}
+  definitions['lockfile-version'].flatten('lockfile-version', {
+    'lockfile-version': '3',
+  }, flat)
+  t.match(flat.lockfileVersion, 3, 'flattens to a number')
+  t.end()
+})