fix: negate error on install without lockfile (#6851)

Change the error message to indicate the wanted lockfile is absent, not
present. This now reflects the actual error.

---------

Co-authored-by: Zoltan Kochan <z@kochan.io>

.changeset/chilled-terms-matter.md

@@ -0,0 +1,6 @@
+---
+"@pnpm/core": patch
+"pnpm": patch
+---
+
+Change the install error message when a lockfile is wanted but absent to indicate the wanted lockfile is absent, not present. This now reflects the actual error [#6851](https://github.com/pnpm/pnpm/pull/6851).

pkg-manager/core/src/install/index.ts

@@ -416,7 +416,7 @@ Note that in CI environments, this setting is enabled by default.`,
           if (!satisfies) {
             if (!ctx.existsWantedLockfile) {
               throw new PnpmError('NO_LOCKFILE',
-                `Cannot install with "frozen-lockfile" because ${WANTED_LOCKFILE} is present`, {
+                `Cannot install with "frozen-lockfile" because ${WANTED_LOCKFILE} is absent`, {
                   hint: 'Note that in CI environments this setting is true by default. If you still need to run install in such cases, use "pnpm install --no-frozen-lockfile"',
                 })
             }

pkg-manager/core/test/install/frozenLockfile.ts

@@ -124,7 +124,7 @@ test(`frozen-lockfile: should fail if no ${WANTED_LOCKFILE} is present`, async (
         'is-positive': '^3.0.0',
       },
     }, await testDefaults({ frozenLockfile: true }))
-  ).rejects.toThrow(`Cannot install with "frozen-lockfile" because ${WANTED_LOCKFILE} is present`)
+  ).rejects.toThrow(`Cannot install with "frozen-lockfile" because ${WANTED_LOCKFILE} is absent`)
 })
 
 test(`prefer-frozen-lockfile: should prefer headless installation when ${WANTED_LOCKFILE} satisfies package.json`, async () => {