Mirror excerpt completion across shells (#1525)

changelog.d/unreleased/1525.fixed.md

@@ -0,0 +1,16 @@
+---
+category: fixed
+issues:
+  - 1525
+affected:
+  - src/CodeIndex/Cli/ConsoleUi.cs
+  - tests/CodeIndex.Tests/ConsoleUiTests.cs
+---
+
+## English
+
+- **`cdidx --completions fish` now lists `--start` / `--end` for `excerpt`, restoring shell parity (#1525)** — the bash and zsh completion scripts already enumerated every `excerpt` flag, but the fish completion omitted `--start` and `--end`, so fish users typing `cdidx excerpt … --st<Tab>` or `--en<Tab>` got no suggestion even though both flags are required by the documented `cdidx excerpt <path> --start <line> [--end <line>] …` signature. The fish script now emits `complete -c cdidx -n '__fish_seen_subcommand_from excerpt' -l start` / `-l end` entries that mirror the bash/zsh tables, and a new `PrintCompletions_ExcerptFlagSetsMatchAcrossShells` test parses each shell's completion output for the `excerpt` branch and asserts the bash, zsh, and fish flag sets are identical (modulo the universal `--help`), so future shell-completion drift is caught at build time instead of in user reports.
+
+## 日本語
+
+- **`cdidx --completions fish` の `excerpt` 補完に `--start` / `--end` を追加し、シェル間で同等の補完を提供するようにしました (#1525)** — bash / zsh の補完スクリプトは `excerpt` の全フラグを列挙していましたが、fish 補完だけ `--start` / `--end` が抜けており、fish ユーザーが `cdidx excerpt … --st<Tab>` や `--en<Tab>` と入力しても補完候補が出ませんでした (これらは `cdidx excerpt <path> --start <line> [--end <line>] …` のドキュメント上必須のフラグです)。fish スクリプトに `complete -c cdidx -n '__fish_seen_subcommand_from excerpt' -l start` / `-l end` を追加して bash / zsh と揃え、さらに新しい `PrintCompletions_ExcerptFlagSetsMatchAcrossShells` テストが各シェルの `excerpt` 分岐から補完対象のフラグ集合を抽出し、bash / zsh / fish のフラグ集合が一致すること (どこでも有効な `--help` は除外) を検証することで、将来の補完スクリプト乖離をユーザー報告ではなくビルド時点で検出できるようにしました。

src/CodeIndex/Cli/ConsoleUi.cs

@@ -806,6 +806,8 @@ private static string GetFishCompletions()
         lines.Add("complete -c cdidx -n '__fish_seen_subcommand_from find' -l query -r -d 'Literal query'");
         lines.Add("complete -c cdidx -n '__fish_seen_subcommand_from find excerpt' -l before -r -d 'Context lines before'");
         lines.Add("complete -c cdidx -n '__fish_seen_subcommand_from find excerpt' -l after -r -d 'Context lines after'");
+        lines.Add("complete -c cdidx -n '__fish_seen_subcommand_from excerpt' -l start -r -d 'Start line'");
+        lines.Add("complete -c cdidx -n '__fish_seen_subcommand_from excerpt' -l end -r -d 'End line'");
         lines.Add("complete -c cdidx -n '__fish_seen_subcommand_from search references excerpt find inspect' -l max-line-width -r -d 'Clamp long single-line payloads (0 disables clamping)'");
         lines.Add("complete -c cdidx -n '__fish_seen_subcommand_from excerpt' -l focus-line -r -d 'Focused line to keep visible when clamping'");
         lines.Add("complete -c cdidx -n '__fish_seen_subcommand_from excerpt' -l focus-column -r -d 'Focused column to keep visible when clamping'");

tests/CodeIndex.Tests/ConsoleUiTests.cs

@@ -1,3 +1,4 @@
+using System.Text.RegularExpressions;
 using CodeIndex.Cli;
 
 namespace CodeIndex.Tests;
@@ -293,6 +294,72 @@ public void PrintCompletions_BashAndZshKeepFocusOptionsExcerptOnly(string shell)
         }
     }
 
+    [Fact]
+    public void PrintCompletions_ExcerptFlagSetsMatchAcrossShells()
+    {
+        var bashExcerpt = ExtractBashSubcommandFlags(ConsoleUi.GetCompletionScript("bash"), "excerpt", "references");
+        var zshExcerpt = ExtractZshSubcommandFlags(ConsoleUi.GetCompletionScript("zsh"), "excerpt", "references");
+        var fishExcerpt = ExtractFishSubcommandFlags(ConsoleUi.GetCompletionScript("fish"), "excerpt");
+
+        // --help is universal in bash but is not enumerated by the zsh/fish scripts;
+        // exclude it from the parity comparison so the flag sets line up cleanly.
+        bashExcerpt.Remove("help");
+
+        Assert.Equal(bashExcerpt, zshExcerpt);
+        Assert.Equal(bashExcerpt, fishExcerpt);
+        // Sanity check: required excerpt flags are present in every shell.
+        foreach (var flag in new[] { "db", "json", "start", "end", "before", "after", "max-line-width", "focus-line", "focus-column", "focus-length" })
+        {
+            Assert.Contains(flag, bashExcerpt);
+            Assert.Contains(flag, zshExcerpt);
+            Assert.Contains(flag, fishExcerpt);
+        }
+    }
+
+    private static SortedSet<string> ExtractBashSubcommandFlags(string script, string subcommand, string nextSubcommand)
+    {
+        var startMarker = $"[ \"$cmd\" = \"{subcommand}\" ]; then";
+        var endMarker = $"[ \"$cmd\" = \"{nextSubcommand}\" ]; then";
+        var branch = ExtractBetween(script, startMarker, endMarker);
+        var quoted = Regex.Match(branch, "compgen -W \"(?<flags>[^\"]*)\"");
+        Assert.True(quoted.Success, $"bash branch for {subcommand} did not contain a compgen list");
+        var flags = new SortedSet<string>(StringComparer.Ordinal);
+        foreach (var token in quoted.Groups["flags"].Value.Split(' ', StringSplitOptions.RemoveEmptyEntries))
+        {
+            if (token.StartsWith("--", StringComparison.Ordinal) && token.Length > 2)
+                flags.Add(token[2..]);
+        }
+        return flags;
+    }
+
+    private static SortedSet<string> ExtractZshSubcommandFlags(string script, string subcommand, string nextSubcommand)
+    {
+        var startMarker = $"[[ $subcmd == {subcommand} ]]; then";
+        var endMarker = $"[[ $subcmd == {nextSubcommand} ]]; then";
+        var branch = ExtractBetween(script, startMarker, endMarker);
+        var flags = new SortedSet<string>(StringComparer.Ordinal);
+        foreach (Match match in Regex.Matches(branch, @"'--(?<name>[a-z][a-z0-9-]*)\["))
+            flags.Add(match.Groups["name"].Value);
+        return flags;
+    }
+
+    private static SortedSet<string> ExtractFishSubcommandFlags(string script, string subcommand)
+    {
+        var flags = new SortedSet<string>(StringComparer.Ordinal);
+        var pattern = new Regex($@"__fish_seen_subcommand_from\s+(?<list>[^']+)'\s+-l\s+(?<flag>[a-z][a-z0-9-]*)\b");
+        foreach (var line in script.Split('\n'))
+        {
+            var match = pattern.Match(line);
+            if (!match.Success)
+                continue;
+            var subcmds = match.Groups["list"].Value.Split(' ', StringSplitOptions.RemoveEmptyEntries);
+            if (Array.IndexOf(subcmds, subcommand) < 0)
+                continue;
+            flags.Add(match.Groups["flag"].Value);
+        }
+        return flags;
+    }
+
     [Fact]
     public void GetCompletionLangs_IncludesWindowsBatchAndYamlAliases()
     {