brontes 0.1.0

Transform any clap CLI into an MCP server.
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
//! Per-OS path resolution for editor configuration files.
//!
//! Each helper mirrors the ophis `internal/cfgmgr/manager/<editor>/<editor>_{darwin,linux,windows}.go`
//! family verbatim, lifted into a single Rust module that is `cfg`-gated by
//! `target_os`. The Rust analog of Go's `os.UserHomeDir()` is
//! [`dirs::home_dir`]; on `None` we take the per-row fallback chain.
//!
//! Cursor and `VSCode` layer their own resolvers next to
//! [`claude_config_path`] following the same `cfg`-gated shape; the trait of
//! "primary path + fallback when home resolution fails" is the surface area
//! every editor shares. `VSCode` and Cursor on Linux do NOT consult
//! `XDG_CONFIG_HOME` — that is Claude-only behavior.

use std::path::PathBuf;

/// Default Claude Desktop config path for the current platform.
///
/// macOS: `$HOME_DIR/Library/Application Support/Claude/claude_desktop_config.json`,
/// falling back to `/Users/$USER/...` when `dirs::home_dir()` returns `None`.
///
/// Linux: respects `$XDG_CONFIG_HOME` (this is the ONLY editor that consults
/// XDG); otherwise `$HOME_DIR/.config/Claude/...`, falling back to
/// `/home/$USER/.config/Claude/...`.
///
/// Windows: reads `$APPDATA`, then `$USERPROFILE\AppData\Roaming\...`, then
/// the literal `C:\Users\Default\AppData\Roaming\...` — no separate home-
/// unresolved branch (the chain is entirely env-driven per
/// `claude_windows.go:9-19`).
#[must_use]
pub fn claude_config_path() -> PathBuf {
    #[cfg(target_os = "macos")]
    {
        let home = dirs::home_dir();
        let user = std::env::var("USER").unwrap_or_default();
        claude_config_path_macos_from(home.as_deref(), &user)
    }
    #[cfg(target_os = "linux")]
    {
        let home = dirs::home_dir();
        let xdg = std::env::var("XDG_CONFIG_HOME").ok();
        let user = std::env::var("USER").unwrap_or_default();
        claude_config_path_linux_from(home.as_deref(), xdg.as_deref(), &user)
    }
    #[cfg(target_os = "windows")]
    {
        let appdata = std::env::var("APPDATA").ok();
        let userprofile = std::env::var("USERPROFILE").ok();
        claude_config_path_windows_from(appdata.as_deref(), userprofile.as_deref())
    }
    // Fallback for non-tier-1 targets (BSD, illumos, etc.): treat as Linux.
    #[cfg(not(any(target_os = "macos", target_os = "linux", target_os = "windows")))]
    {
        let home = dirs::home_dir();
        let xdg = std::env::var("XDG_CONFIG_HOME").ok();
        let user = std::env::var("USER").unwrap_or_default();
        claude_config_path_linux_from(home.as_deref(), xdg.as_deref(), &user)
    }
}

// ── pure path builders ───────────────────────────────────────────────────
// Each per-OS resolver takes every input as a parameter (testable without
// process-env mutation). The public [`claude_config_path`] wrapper pulls
// those inputs from `dirs::home_dir()` and `std::env::var(...)`. Reading
// env vars is safe; only mutating them is `unsafe` in Rust 2024 — and the
// crate forbids `unsafe_code` at the root.

/// Pure macOS resolver. `home` is `Some` when `dirs::home_dir()` resolves;
/// `user` is the value of `$USER` (used only in the home-unresolved path).
///
/// `cfg`-gated on macOS or `test` so the function compiles (and runs its
/// tests) on every host while the linux/windows lib builds don't see it as
/// dead code.
#[cfg(any(target_os = "macos", test))]
fn claude_config_path_macos_from(home: Option<&std::path::Path>, user: &str) -> PathBuf {
    if let Some(home) = home {
        return home
            .join("Library")
            .join("Application Support")
            .join("Claude")
            .join("claude_desktop_config.json");
    }
    PathBuf::from("/Users")
        .join(user)
        .join("Library")
        .join("Application Support")
        .join("Claude")
        .join("claude_desktop_config.json")
}

/// Pure Linux resolver. `home` is `Some` when `dirs::home_dir()` resolves;
/// `xdg_config_home` is the value of `$XDG_CONFIG_HOME` (empty/`None`
/// triggers the `$HOME/.config` fallback); `user` is `$USER` for the
/// home-unresolved branch.
///
/// `cfg`-gated on Linux (or any non-tier-1 target, which also routes here)
/// or `test` so the function compiles (and runs its tests) on every host
/// while macos/windows lib builds don't see it as dead code.
#[cfg(any(
    target_os = "linux",
    not(any(target_os = "macos", target_os = "windows")),
    test
))]
fn claude_config_path_linux_from(
    home: Option<&std::path::Path>,
    xdg_config_home: Option<&str>,
    user: &str,
) -> PathBuf {
    if let Some(home) = home {
        // Claude on Linux is the ONLY editor that consults XDG_CONFIG_HOME.
        let cfg_root = match xdg_config_home {
            Some(v) if !v.is_empty() => PathBuf::from(v),
            _ => home.join(".config"),
        };
        return cfg_root.join("Claude").join("claude_desktop_config.json");
    }
    PathBuf::from("/home")
        .join(user)
        .join(".config")
        .join("Claude")
        .join("claude_desktop_config.json")
}

/// Pure Windows resolver. Mirrors `claude_windows.go:9-19` — APPDATA wins,
/// then USERPROFILE + `AppData\Roaming`, then the literal
/// `C:\Users\Default\AppData\Roaming`. Each input is an `Option<&str>` so
/// the resolver is testable without process-env mutation.
///
/// `cfg`-gated on Windows or `test` so the function compiles (and runs its
/// tests) on every host while the linux/macos lib builds don't see it as
/// dead code.
#[cfg(any(target_os = "windows", test))]
fn claude_config_path_windows_from(appdata: Option<&str>, userprofile: Option<&str>) -> PathBuf {
    if let Some(v) = appdata.filter(|s| !s.is_empty()) {
        return PathBuf::from(v)
            .join("Claude")
            .join("claude_desktop_config.json");
    }
    if let Some(v) = userprofile.filter(|s| !s.is_empty()) {
        return PathBuf::from(v)
            .join("AppData")
            .join("Roaming")
            .join("Claude")
            .join("claude_desktop_config.json");
    }
    PathBuf::from(r"C:\Users\Default\AppData\Roaming")
        .join("Claude")
        .join("claude_desktop_config.json")
}

/// Default Cursor user-mode `mcp.json` path for the current platform.
///
/// macOS: `$HOME_DIR/.cursor/mcp.json`, falling back to
/// `/Users/$USER/.cursor/mcp.json` when `dirs::home_dir()` returns `None`.
///
/// Linux: `$HOME_DIR/.cursor/mcp.json`, falling back to
/// `/home/$USER/.cursor/mcp.json` when home is unresolved. Cursor on Linux
/// does NOT consult `XDG_CONFIG_HOME` — that's Claude-only behavior.
///
/// Windows: `$HOME_DIR/.cursor/mcp.json` (where `$HOME_DIR` is `dirs::home_dir`,
/// which on Windows resolves `%USERPROFILE%`), falling back to
/// `$USERPROFILE\.cursor\mcp.json` from a direct env read when home is
/// unresolved.
#[must_use]
pub fn cursor_config_path() -> PathBuf {
    #[cfg(target_os = "macos")]
    {
        let home = dirs::home_dir();
        let user = std::env::var("USER").unwrap_or_default();
        cursor_config_path_macos_from(home.as_deref(), &user)
    }
    #[cfg(target_os = "linux")]
    {
        let home = dirs::home_dir();
        let user = std::env::var("USER").unwrap_or_default();
        cursor_config_path_linux_from(home.as_deref(), &user)
    }
    #[cfg(target_os = "windows")]
    {
        let home = dirs::home_dir();
        let userprofile = std::env::var("USERPROFILE").ok();
        cursor_config_path_windows_from(home.as_deref(), userprofile.as_deref())
    }
    // Fallback for non-tier-1 targets (BSD, illumos, etc.): treat as Linux.
    #[cfg(not(any(target_os = "macos", target_os = "linux", target_os = "windows")))]
    {
        let home = dirs::home_dir();
        let user = std::env::var("USER").unwrap_or_default();
        cursor_config_path_linux_from(home.as_deref(), &user)
    }
}

/// Cursor workspace-mode `mcp.json` path: `$CWD/.cursor/mcp.json`, falling
/// back to the relative `.cursor/mcp.json` when `std::env::current_dir()`
/// fails (matches ophis behavior).
#[must_use]
pub fn cursor_workspace_path() -> PathBuf {
    cursor_workspace_path_from(std::env::current_dir().ok().as_deref())
}

/// Pure macOS resolver for Cursor user-mode. `home` is `Some` when
/// `dirs::home_dir()` resolves; `user` is `$USER` for the home-unresolved
/// branch.
#[cfg(any(target_os = "macos", test))]
fn cursor_config_path_macos_from(home: Option<&std::path::Path>, user: &str) -> PathBuf {
    if let Some(home) = home {
        return home.join(".cursor").join("mcp.json");
    }
    PathBuf::from("/Users")
        .join(user)
        .join(".cursor")
        .join("mcp.json")
}

/// Pure Linux resolver for Cursor user-mode. `home` is `Some` when
/// `dirs::home_dir()` resolves; `user` is `$USER` for the home-unresolved
/// branch. Cursor on Linux does NOT consult `XDG_CONFIG_HOME`.
#[cfg(any(
    target_os = "linux",
    not(any(target_os = "macos", target_os = "windows")),
    test
))]
fn cursor_config_path_linux_from(home: Option<&std::path::Path>, user: &str) -> PathBuf {
    if let Some(home) = home {
        return home.join(".cursor").join("mcp.json");
    }
    PathBuf::from("/home")
        .join(user)
        .join(".cursor")
        .join("mcp.json")
}

/// Pure Windows resolver for Cursor user-mode. `home` is `Some` when
/// `dirs::home_dir()` resolves; `userprofile` is `$USERPROFILE` for the
/// home-unresolved branch.
#[cfg(any(target_os = "windows", test))]
fn cursor_config_path_windows_from(
    home: Option<&std::path::Path>,
    userprofile: Option<&str>,
) -> PathBuf {
    if let Some(home) = home {
        return home.join(".cursor").join("mcp.json");
    }
    if let Some(v) = userprofile.filter(|s| !s.is_empty()) {
        return PathBuf::from(v).join(".cursor").join("mcp.json");
    }
    // No home, no USERPROFILE — match the relative fallback so we still
    // produce *some* path the caller can present to the user (the error
    // surfaces at file open).
    PathBuf::from(".cursor").join("mcp.json")
}

/// Pure workspace resolver. `cwd` is `Some` when `std::env::current_dir()`
/// resolves; `None` (e.g. cwd deleted out from under us) falls back to the
/// relative `.cursor/mcp.json`.
fn cursor_workspace_path_from(cwd: Option<&std::path::Path>) -> PathBuf {
    if let Some(cwd) = cwd {
        return cwd.join(".cursor").join("mcp.json");
    }
    PathBuf::from(".cursor").join("mcp.json")
}

/// Default `VSCode` user-mode `mcp.json` path for the current platform.
///
/// macOS: `$HOME_DIR/Library/Application Support/Code/User/mcp.json`,
/// falling back to `/Users/$USER/Library/Application Support/Code/User/mcp.json`
/// when `dirs::home_dir()` returns `None`.
///
/// Linux: `$HOME_DIR/.config/Code/User/mcp.json`, falling back to
/// `/home/$USER/.config/Code/User/mcp.json` when home is unresolved.
/// `VSCode` on Linux does NOT consult `XDG_CONFIG_HOME` — that's Claude-only
/// behavior.
///
/// Windows: `$HOME_DIR/AppData/Roaming/Code/User/mcp.json` (where
/// `$HOME_DIR` is `dirs::home_dir`, which on Windows resolves
/// `%USERPROFILE%`), falling back to
/// `$USERPROFILE/AppData/Roaming/Code/User/mcp.json` from a direct env read
/// when home is unresolved.
#[must_use]
pub fn vscode_config_path() -> PathBuf {
    #[cfg(target_os = "macos")]
    {
        let home = dirs::home_dir();
        let user = std::env::var("USER").unwrap_or_default();
        vscode_config_path_macos_from(home.as_deref(), &user)
    }
    #[cfg(target_os = "linux")]
    {
        let home = dirs::home_dir();
        let user = std::env::var("USER").unwrap_or_default();
        vscode_config_path_linux_from(home.as_deref(), &user)
    }
    #[cfg(target_os = "windows")]
    {
        let home = dirs::home_dir();
        let userprofile = std::env::var("USERPROFILE").ok();
        vscode_config_path_windows_from(home.as_deref(), userprofile.as_deref())
    }
    // Fallback for non-tier-1 targets (BSD, illumos, etc.): treat as Linux.
    #[cfg(not(any(target_os = "macos", target_os = "linux", target_os = "windows")))]
    {
        let home = dirs::home_dir();
        let user = std::env::var("USER").unwrap_or_default();
        vscode_config_path_linux_from(home.as_deref(), &user)
    }
}

/// `VSCode` workspace-mode `mcp.json` path: `$CWD/.vscode/mcp.json`, falling
/// back to the relative `.vscode/mcp.json` when `std::env::current_dir()`
/// fails (matches ophis behavior).
#[must_use]
pub fn vscode_workspace_path() -> PathBuf {
    vscode_workspace_path_from(std::env::current_dir().ok().as_deref())
}

/// Pure macOS resolver for `VSCode` user-mode. `home` is `Some` when
/// `dirs::home_dir()` resolves; `user` is `$USER` for the home-unresolved
/// branch.
#[cfg(any(target_os = "macos", test))]
fn vscode_config_path_macos_from(home: Option<&std::path::Path>, user: &str) -> PathBuf {
    if let Some(home) = home {
        return home
            .join("Library")
            .join("Application Support")
            .join("Code")
            .join("User")
            .join("mcp.json");
    }
    PathBuf::from("/Users")
        .join(user)
        .join("Library")
        .join("Application Support")
        .join("Code")
        .join("User")
        .join("mcp.json")
}

/// Pure Linux resolver for `VSCode` user-mode. `home` is `Some` when
/// `dirs::home_dir()` resolves; `user` is `$USER` for the home-unresolved
/// branch. `VSCode` on Linux does NOT consult `XDG_CONFIG_HOME`.
#[cfg(any(
    target_os = "linux",
    not(any(target_os = "macos", target_os = "windows")),
    test
))]
fn vscode_config_path_linux_from(home: Option<&std::path::Path>, user: &str) -> PathBuf {
    if let Some(home) = home {
        return home
            .join(".config")
            .join("Code")
            .join("User")
            .join("mcp.json");
    }
    PathBuf::from("/home")
        .join(user)
        .join(".config")
        .join("Code")
        .join("User")
        .join("mcp.json")
}

/// Pure Windows resolver for `VSCode` user-mode. `home` is `Some` when
/// `dirs::home_dir()` resolves; `userprofile` is `$USERPROFILE` for the
/// home-unresolved branch.
#[cfg(any(target_os = "windows", test))]
fn vscode_config_path_windows_from(
    home: Option<&std::path::Path>,
    userprofile: Option<&str>,
) -> PathBuf {
    if let Some(home) = home {
        return home
            .join("AppData")
            .join("Roaming")
            .join("Code")
            .join("User")
            .join("mcp.json");
    }
    if let Some(v) = userprofile.filter(|s| !s.is_empty()) {
        return PathBuf::from(v)
            .join("AppData")
            .join("Roaming")
            .join("Code")
            .join("User")
            .join("mcp.json");
    }
    // No home, no USERPROFILE — match Cursor's relative fallback shape
    // (the home-prefix dropped) so we still produce *some* path the caller
    // can present to the user. The error surfaces at file open. ophis's
    // `vscode_windows.go` has no `C:\Users\Default` literal (that pattern
    // is Claude-only), so a relative fallback is more
    // faithful to the parity goal than inventing one.
    PathBuf::from("AppData")
        .join("Roaming")
        .join("Code")
        .join("User")
        .join("mcp.json")
}

/// Pure workspace resolver for `VSCode`. `cwd` is `Some` when
/// `std::env::current_dir()` resolves; `None` (e.g. cwd deleted out from
/// under us) falls back to the relative `.vscode/mcp.json`.
fn vscode_workspace_path_from(cwd: Option<&std::path::Path>) -> PathBuf {
    if let Some(cwd) = cwd {
        return cwd.join(".vscode").join("mcp.json");
    }
    PathBuf::from(".vscode").join("mcp.json")
}

/// Strip exactly one trailing extension from the file-stem portion of a
/// path, matching ophis `manager.DeriveServerName` (`utils.go:13-20`).
///
/// `foo` -> `foo`. `foo.exe` -> `foo`. `foo.tar.exe` -> `foo.tar`.
/// `/usr/local/bin/myapp.exe` -> `myapp`. Used by `mcp claude {enable,disable}`
/// to derive the server name from the current executable when the user did
/// not pass `--server-name`.
#[must_use]
pub fn derive_server_name(executable_path: &std::path::Path) -> String {
    let base = executable_path
        .file_name()
        .map(|s| s.to_string_lossy().into_owned())
        .unwrap_or_default();
    // ophis Go: filepath.Ext on the basename returns the FINAL extension
    // including the dot, or empty when none. We trim one trailing extension.
    if let Some(idx) = base.rfind('.') {
        // Guard against a leading dot (e.g. ".bashrc") which Go's filepath.Ext
        // treats as no extension; ophis's behavior on such a name is "return
        // basename verbatim". `rfind('.') == Some(0)` indicates a dotfile.
        if idx == 0 {
            return base;
        }
        return base[..idx].to_string();
    }
    base
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::path::Path;

    #[test]
    fn derive_server_name_plain_basename() {
        assert_eq!(
            derive_server_name(Path::new("/usr/local/bin/myapp")),
            "myapp"
        );
    }

    #[test]
    fn derive_server_name_strips_exe() {
        assert_eq!(
            derive_server_name(Path::new("/usr/local/bin/myapp.exe")),
            "myapp"
        );
    }

    #[test]
    fn derive_server_name_strips_one_extension_only() {
        assert_eq!(derive_server_name(Path::new("/tmp/foo.tar.exe")), "foo.tar");
    }

    #[test]
    fn derive_server_name_relative_path() {
        assert_eq!(derive_server_name(Path::new("./myapp")), "myapp");
    }

    #[test]
    fn derive_server_name_no_directory() {
        assert_eq!(derive_server_name(Path::new("kubectl")), "kubectl");
    }

    #[test]
    fn derive_server_name_dotfile_returned_verbatim() {
        // ophis filepath.Ext on ".bashrc" returns "" so the basename is
        // returned verbatim; we mirror that intent (no leading-dot strip).
        assert_eq!(derive_server_name(Path::new(".bashrc")), ".bashrc");
    }

    // ── per-OS pure-resolver tests. Each test drives the `*_from` helper
    // with synthetic args so no process-env mutation is needed — the crate
    // forbids `unsafe_code`, and Rust 2024 marks `std::env::set_var` as
    // `unsafe`. Driving the pure functions directly sidesteps that
    // conflict and runs on every host regardless of `target_os`. ──────

    // ── macOS pure resolver ───────────────────────────────────────────

    #[test]
    fn macos_uses_application_support_when_home_resolves() {
        let path = claude_config_path_macos_from(Some(Path::new("/Users/synthetic")), "synthetic");
        assert_eq!(
            path,
            PathBuf::from(
                "/Users/synthetic/Library/Application Support/Claude/claude_desktop_config.json"
            )
        );
    }

    #[test]
    fn macos_falls_back_to_users_user_when_home_unresolved() {
        let path = claude_config_path_macos_from(None, "fallback");
        assert_eq!(
            path,
            PathBuf::from(
                "/Users/fallback/Library/Application Support/Claude/claude_desktop_config.json"
            )
        );
    }

    // ── Linux pure resolver ───────────────────────────────────────────

    #[test]
    fn linux_uses_dollar_home_dot_config_when_xdg_unset() {
        let path =
            claude_config_path_linux_from(Some(Path::new("/home/synthetic")), None, "synthetic");
        assert_eq!(
            path,
            PathBuf::from("/home/synthetic/.config/Claude/claude_desktop_config.json")
        );
    }

    #[test]
    fn linux_uses_dollar_home_dot_config_when_xdg_empty() {
        // Empty XDG_CONFIG_HOME must fall through to the $HOME/.config path
        // (matches ophis behavior on `os.Getenv` returning the empty string).
        let path = claude_config_path_linux_from(
            Some(Path::new("/home/synthetic")),
            Some(""),
            "synthetic",
        );
        assert_eq!(
            path,
            PathBuf::from("/home/synthetic/.config/Claude/claude_desktop_config.json")
        );
    }

    #[test]
    fn linux_honors_xdg_config_home() {
        let path = claude_config_path_linux_from(
            Some(Path::new("/home/synthetic")),
            Some("/custom/xdg"),
            "synthetic",
        );
        assert_eq!(
            path,
            PathBuf::from("/custom/xdg/Claude/claude_desktop_config.json")
        );
    }

    #[test]
    fn linux_falls_back_to_home_user_when_home_unresolved() {
        let path = claude_config_path_linux_from(None, None, "fallback");
        assert_eq!(
            path,
            PathBuf::from("/home/fallback/.config/Claude/claude_desktop_config.json")
        );
    }

    // ── Windows pure resolver ─────────────────────────────────────────

    #[test]
    fn windows_prefers_appdata() {
        let path = claude_config_path_windows_from(
            Some(r"C:\Users\synth\AppData\Roaming"),
            Some(r"C:\Users\synth"),
        );
        let components: Vec<String> = path
            .components()
            .map(|c| c.as_os_str().to_string_lossy().into_owned())
            .collect();
        assert!(components.contains(&"Claude".to_string()));
        assert!(components.contains(&"claude_desktop_config.json".to_string()));
        assert!(
            components.iter().any(|c| c.contains("Roaming")),
            "must include the Roaming segment from APPDATA, got {components:?}"
        );
    }

    #[test]
    fn windows_falls_back_to_userprofile_when_appdata_empty() {
        let path = claude_config_path_windows_from(Some(""), Some(r"C:\Users\synth"));
        let s = path.to_string_lossy();
        assert!(s.contains("AppData"), "got {s}");
        assert!(s.contains("Roaming"), "got {s}");
        assert!(s.contains("Claude"), "got {s}");
    }

    #[test]
    fn windows_falls_back_to_userprofile_when_appdata_none() {
        let path = claude_config_path_windows_from(None, Some(r"C:\Users\synth"));
        let s = path.to_string_lossy();
        assert!(s.contains("AppData"), "got {s}");
        assert!(s.contains("Roaming"), "got {s}");
        assert!(s.contains("Claude"), "got {s}");
    }

    #[test]
    fn windows_default_users_fallback() {
        // Both env vars missing → literal C:\Users\Default\AppData\Roaming.
        let path = claude_config_path_windows_from(None, None);
        let s = path.to_string_lossy().into_owned();
        assert!(s.contains("Default"), "got {s}");
        assert!(s.contains("Claude"), "got {s}");
    }

    // ── Cursor (user) macOS resolver ──────────────────────────────────

    #[test]
    fn cursor_macos_uses_home_dot_cursor_when_home_resolves() {
        let path = cursor_config_path_macos_from(Some(Path::new("/Users/synthetic")), "synthetic");
        assert_eq!(path, PathBuf::from("/Users/synthetic/.cursor/mcp.json"));
    }

    #[test]
    fn cursor_macos_falls_back_to_users_user_when_home_unresolved() {
        let path = cursor_config_path_macos_from(None, "fallback");
        assert_eq!(path, PathBuf::from("/Users/fallback/.cursor/mcp.json"));
    }

    // ── Cursor (user) Linux resolver ──────────────────────────────────

    #[test]
    fn cursor_linux_uses_home_dot_cursor_when_home_resolves() {
        let path = cursor_config_path_linux_from(Some(Path::new("/home/synthetic")), "synthetic");
        assert_eq!(path, PathBuf::from("/home/synthetic/.cursor/mcp.json"));
    }

    #[test]
    fn cursor_linux_falls_back_to_home_user_when_home_unresolved() {
        let path = cursor_config_path_linux_from(None, "fallback");
        assert_eq!(path, PathBuf::from("/home/fallback/.cursor/mcp.json"));
    }

    #[test]
    fn cursor_linux_does_not_consult_xdg() {
        // Cursor on Linux must NOT consult XDG_CONFIG_HOME.
        // The resolver signature doesn't even accept an XDG argument — this
        // test pins the surface so a future "let's consolidate the linux
        // resolvers" refactor doesn't accidentally route Cursor through XDG.
        let path = cursor_config_path_linux_from(Some(Path::new("/home/synthetic")), "synthetic");
        let s = path.to_string_lossy();
        assert!(
            !s.contains(".config"),
            "must not route through .config: {s}"
        );
    }

    // ── Cursor (user) Windows resolver ────────────────────────────────

    #[test]
    fn cursor_windows_uses_home_when_resolves() {
        let path = cursor_config_path_windows_from(
            Some(Path::new(r"C:\Users\synth")),
            Some(r"C:\Users\synth"),
        );
        let s = path.to_string_lossy();
        assert!(s.contains(".cursor"), "got {s}");
        assert!(s.contains("mcp.json"), "got {s}");
    }

    #[test]
    fn cursor_windows_falls_back_to_userprofile_when_home_unresolved() {
        let path = cursor_config_path_windows_from(None, Some(r"C:\Users\synth"));
        let s = path.to_string_lossy();
        assert!(s.contains(r"C:\Users\synth"), "got {s}");
        assert!(s.contains(".cursor"), "got {s}");
    }

    #[test]
    fn cursor_windows_relative_fallback_when_all_unresolved() {
        // No home, no USERPROFILE — fall back to relative `.cursor/mcp.json`
        // so the caller still gets a usable PathBuf; error surfaces at open.
        let path = cursor_config_path_windows_from(None, None);
        assert_eq!(path, PathBuf::from(r".cursor").join("mcp.json"));
    }

    // ── Cursor workspace-mode resolver ────────────────────────────────

    #[test]
    fn cursor_workspace_uses_cwd_when_resolves() {
        let path = cursor_workspace_path_from(Some(Path::new("/tmp/myproj")));
        assert_eq!(path, PathBuf::from("/tmp/myproj/.cursor/mcp.json"));
    }

    #[test]
    fn cursor_workspace_falls_back_to_relative_when_cwd_unresolved() {
        let path = cursor_workspace_path_from(None);
        assert_eq!(path, PathBuf::from(".cursor").join("mcp.json"));
    }

    // ── VSCode (user) macOS resolver ──────────────────────────────────

    #[test]
    fn vscode_macos_uses_application_support_code_when_home_resolves() {
        let path = vscode_config_path_macos_from(Some(Path::new("/Users/synthetic")), "synthetic");
        assert_eq!(
            path,
            PathBuf::from("/Users/synthetic/Library/Application Support/Code/User/mcp.json")
        );
    }

    #[test]
    fn vscode_macos_falls_back_to_users_user_when_home_unresolved() {
        let path = vscode_config_path_macos_from(None, "fallback");
        assert_eq!(
            path,
            PathBuf::from("/Users/fallback/Library/Application Support/Code/User/mcp.json")
        );
    }

    // ── VSCode (user) Linux resolver ──────────────────────────────────

    #[test]
    fn vscode_linux_uses_home_dot_config_code_when_home_resolves() {
        let path = vscode_config_path_linux_from(Some(Path::new("/home/synthetic")), "synthetic");
        assert_eq!(
            path,
            PathBuf::from("/home/synthetic/.config/Code/User/mcp.json")
        );
    }

    #[test]
    fn vscode_linux_falls_back_to_home_user_when_home_unresolved() {
        let path = vscode_config_path_linux_from(None, "fallback");
        assert_eq!(
            path,
            PathBuf::from("/home/fallback/.config/Code/User/mcp.json")
        );
    }

    #[test]
    fn vscode_linux_does_not_consult_xdg() {
        // VSCode on Linux must NOT consult XDG_CONFIG_HOME.
        // The resolver signature doesn't even accept an XDG argument — this
        // test pins the surface so a future "let's consolidate the linux
        // resolvers" refactor doesn't accidentally route VSCode through XDG.
        let path = vscode_config_path_linux_from(Some(Path::new("/home/synthetic")), "synthetic");
        // The resolver MUST produce `$HOME/.config/Code/User/mcp.json` — the
        // `.config` segment here is part of the VSCode-specific path layout,
        // NOT an XDG redirect. Compare component-wise (via PathBuf equality)
        // so the assertion remains portable across host OSes.
        assert_eq!(
            path,
            PathBuf::from("/home/synthetic/.config/Code/User/mcp.json")
        );
    }

    // ── VSCode (user) Windows resolver ────────────────────────────────

    #[test]
    fn vscode_windows_uses_home_when_resolves() {
        let path = vscode_config_path_windows_from(
            Some(Path::new(r"C:\Users\synth")),
            Some(r"C:\Users\synth"),
        );
        let s = path.to_string_lossy();
        assert!(s.contains("AppData"), "got {s}");
        assert!(s.contains("Roaming"), "got {s}");
        assert!(s.contains("Code"), "got {s}");
        assert!(s.contains("User"), "got {s}");
        assert!(s.contains("mcp.json"), "got {s}");
    }

    #[test]
    fn vscode_windows_falls_back_to_userprofile_when_home_unresolved() {
        let path = vscode_config_path_windows_from(None, Some(r"C:\Users\synth"));
        let s = path.to_string_lossy();
        assert!(s.contains(r"C:\Users\synth"), "got {s}");
        assert!(s.contains("AppData"), "got {s}");
        assert!(s.contains("Roaming"), "got {s}");
        assert!(s.contains("Code"), "got {s}");
        assert!(s.contains("User"), "got {s}");
        assert!(s.contains("mcp.json"), "got {s}");
    }

    #[test]
    fn vscode_windows_relative_fallback_when_all_unresolved() {
        // No home, no USERPROFILE — fall back to a relative path with the
        // home-prefix dropped, mirroring Cursor's tertiary shape. ophis's
        // `vscode_windows.go` has no `C:\Users\Default` literal (that
        // pattern is Claude-only), so we do not invent
        // an absolute fallback here. The error surfaces at file open.
        let path = vscode_config_path_windows_from(None, None);
        assert_eq!(
            path,
            PathBuf::from("AppData")
                .join("Roaming")
                .join("Code")
                .join("User")
                .join("mcp.json")
        );
        assert!(path.is_relative(), "tertiary fallback must be relative");
    }

    // ── VSCode workspace-mode resolver ────────────────────────────────

    #[test]
    fn vscode_workspace_uses_cwd_when_resolves() {
        let path = vscode_workspace_path_from(Some(Path::new("/tmp/myproj")));
        assert_eq!(path, PathBuf::from("/tmp/myproj/.vscode/mcp.json"));
    }

    #[test]
    fn vscode_workspace_falls_back_to_relative_when_cwd_unresolved() {
        let path = vscode_workspace_path_from(None);
        assert_eq!(path, PathBuf::from(".vscode").join("mcp.json"));
    }
}