fix(shell-completion): give correct suggestions when command line ends with a space (#10607)

* fix(shell-completion): give correct suggestions when command line ends with a space

fixes an issue where if you tried to complete any part of any subcommand
with a space before <TAB> (eg: `pnpm run <TAB>`, `pnpm rm react <TAB>`),
pnpm would give you suggestions for the root command, as if you had
typed `pnpm <TAB>`

close #7964
close #5426

---------

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

.changeset/young-radios-fly.md

@@ -0,0 +1,5 @@
+---
+"@pnpm/plugin-commands-completion": patch
+---
+
+Give correct suggestions when command line ends with a space. #[10607](https://github.com/pnpm/pnpm/pull/10607/changes)

completion/plugin-commands-completion/src/completionServer.ts

@@ -26,10 +26,7 @@ export function createCompletionServer (
     const env = tabtab.parseEnv(process.env)
     if (!env.complete) return
 
-    // Parse only words that are before the pointer and finished.
-    // Finished means that there's at least one space between the word and pointer
-    const finishedArgv = env.partial.slice(0, -env.lastPartial.length)
-    const inputArgv = splitCmd(finishedArgv).slice(1)
+    const inputArgv = splitCmd(stripPartialWord(env)).slice(1)
     // We cannot autocomplete what a user types after "pnpm test --"
     if (inputArgv.includes('--')) return
     const { params, options, cmd } = await opts.parseCliArgs(inputArgv)
@@ -48,3 +45,14 @@ export function createCompletionServer (
     )
   }
 }
+
+/**
+ * Returns the portion of the command line that consists of fully typed words,
+ */
+function stripPartialWord (env: { partial: string, lastPartial: string }): string {
+  if (env.lastPartial.length > 0) {
+    // stripping any word the user is currently typing.
+    return env.partial.slice(0, -env.lastPartial.length)
+  }
+  return env.partial
+}