Opinionated OCaml linter with Merlin integration for code quality, naming conventions, and style checks
merlint: complete E8xx interop testing rules (13 rules total)
New rules enforce the /interop-testing skill standards:
Structure:
E800 Missing generate.sh wrapper
E801 Dir named after language instead of oracle tool
E802 Missing committed traces / (source_tree traces) dep
E803 Test shells out to external tool (not replay-only)
Reproducibility:
E805 Python oracle missing requirements.txt
E806 Go oracle missing go.mod
E807 Rust oracle missing Cargo.toml
E835 pip install --break-system-packages (no venv)
Dune integration:
E810 Missing regen-traces alias
E815 REGEN_TRACES env var sentinel
CSV hygiene:
E820 Hand-rolled CSV parsing (use csvt)
E825 CSV traces without csvt dependency in dune
Generator quality:
E830 Inlined algorithm in generator (not calling oracle API)
+230
+41
lib/rules/e802.ml
+41
lib/rules/e802.ml
···
1
+
(** E802: Interop test missing committed traces *)
2
+
3
+
type payload = { dir : string; reason : string }
4
+
5
+
let check (ctx : Context.project) =
6
+
let dirs = Interop.find_oracle_dirs ctx.project_root in
7
+
List.filter_map
8
+
(fun (d : Interop.oracle_dir) ->
9
+
if not d.has_traces then
10
+
Some
11
+
(Issue.v
12
+
{
13
+
dir = d.path;
14
+
reason = "missing traces/ directory — traces must be committed";
15
+
})
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else if d.has_dune then
17
+
let dune = Interop.dune_content d.path in
18
+
if not (Astring.String.is_infix ~affix:"source_tree traces" dune) then
19
+
Some
20
+
(Issue.v
21
+
{
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+
dir = d.path;
23
+
reason =
24
+
"dune test stanza missing (source_tree traces) dep — test \
25
+
must run from committed traces";
26
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})
27
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else None
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else None)
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+
dirs
30
+
31
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let pp ppf { dir; reason } = Fmt.pf ppf "Interop test %s: %s" dir reason
32
+
33
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let rule =
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Rule.v ~code:"E802" ~title:"Interop test not replay-only"
35
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~category:Interop_testing
36
+
~hint:
37
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"Traces must be committed to git. The test stanza must depend on \
38
+
(source_tree traces) so tests run from traces alone — the external tool \
39
+
is NOT required at test time. This is the 'generate once, replay \
40
+
always' principle."
41
+
~examples:[] ~pp (Project check)
+45
lib/rules/e803.ml
+45
lib/rules/e803.ml
···
1
+
(** E803: Interop test shells out to external tool *)
2
+
3
+
type payload = { dir : string; pattern : string }
4
+
5
+
let shell_patterns =
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[
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"Sys.command";
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+
"Unix.system";
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+
"Unix.create_process";
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"Unix.open_process";
11
+
"Eio.Process";
12
+
"Eio_process";
13
+
]
14
+
15
+
let check (ctx : Context.project) =
16
+
let dirs = Interop.find_oracle_dirs ctx.project_root in
17
+
List.filter_map
18
+
(fun (d : Interop.oracle_dir) ->
19
+
if d.has_test_ml then
20
+
let content = Interop.test_content d.path in
21
+
let found =
22
+
List.find_opt
23
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(fun pat -> Astring.String.is_infix ~affix:pat content)
24
+
shell_patterns
25
+
in
26
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match found with
27
+
| Some pattern -> Some (Issue.v { dir = d.path; pattern })
28
+
| None -> None
29
+
else None)
30
+
dirs
31
+
32
+
let pp ppf { dir; pattern } =
33
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Fmt.pf ppf
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"Interop test %s/test.ml calls %s — test must run from traces alone" dir
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+
pattern
36
+
37
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let rule =
38
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Rule.v ~code:"E803" ~title:"Interop test requires external tool"
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~category:Interop_testing
40
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~hint:
41
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"Interop tests must run from committed traces without needing the \
42
+
external tool at test time. The test.ml should only read trace files, \
43
+
never shell out to run the oracle. If you need the oracle, put it in \
44
+
the generator script."
45
+
~examples:[] ~pp (Project check)
+28
lib/rules/e806.ml
+28
lib/rules/e806.ml
···
1
+
(** E806: Go oracle missing go.mod *)
2
+
3
+
type payload = { dir : string }
4
+
5
+
let check (ctx : Context.project) =
6
+
let dirs = Interop.find_oracle_dirs ctx.project_root in
7
+
List.filter_map
8
+
(fun (d : Interop.oracle_dir) ->
9
+
let scripts = Filename.concat d.path "scripts" in
10
+
let has_go =
11
+
try
12
+
Sys.readdir scripts |> Array.to_list
13
+
|> List.exists (fun f -> Filename.check_suffix f ".go")
14
+
with Sys_error _ -> false
15
+
in
16
+
let has_go_mod = Sys.file_exists (Filename.concat scripts "go.mod") in
17
+
if has_go && not has_go_mod then Some (Issue.v { dir = d.path }) else None)
18
+
dirs
19
+
20
+
let pp ppf { dir } = Fmt.pf ppf "Go oracle %s/scripts/ missing go.mod" dir
21
+
22
+
let rule =
23
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Rule.v ~code:"E806" ~title:"Missing go.mod" ~category:Interop_testing
24
+
~hint:
25
+
"Go oracles must pin the upstream module in go.mod with a tagged version \
26
+
or pseudo-version. This ensures reproducible trace generation without \
27
+
depending on $GOPATH or local clones."
28
+
~examples:[] ~pp (Project check)
+37
lib/rules/e807.ml
+37
lib/rules/e807.ml
···
1
+
(** E807: Rust oracle missing Cargo.toml *)
2
+
3
+
type payload = { dir : string }
4
+
5
+
let check (ctx : Context.project) =
6
+
let dirs = Interop.find_oracle_dirs ctx.project_root in
7
+
List.filter_map
8
+
(fun (d : Interop.oracle_dir) ->
9
+
let scripts = Filename.concat d.path "scripts" in
10
+
let has_rust =
11
+
try
12
+
let files = Sys.readdir scripts |> Array.to_list in
13
+
List.exists (fun f -> Filename.check_suffix f ".rs") files
14
+
||
15
+
let src = Filename.concat scripts "src" in
16
+
Sys.file_exists src && Sys.is_directory src
17
+
&&
18
+
try
19
+
Sys.readdir src |> Array.to_list
20
+
|> List.exists (fun f -> Filename.check_suffix f ".rs")
21
+
with Sys_error _ -> false
22
+
with Sys_error _ -> false
23
+
in
24
+
let has_cargo = Sys.file_exists (Filename.concat scripts "Cargo.toml") in
25
+
if has_rust && not has_cargo then Some (Issue.v { dir = d.path })
26
+
else None)
27
+
dirs
28
+
29
+
let pp ppf { dir } = Fmt.pf ppf "Rust oracle %s/scripts/ missing Cargo.toml" dir
30
+
31
+
let rule =
32
+
Rule.v ~code:"E807" ~title:"Missing Cargo.toml" ~category:Interop_testing
33
+
~hint:
34
+
"Rust oracles must pin the upstream crate in Cargo.toml with a tagged \
35
+
version or git rev. This ensures reproducible trace generation without \
36
+
depending on local checkouts."
37
+
~examples:[] ~pp (Project check)
+35
lib/rules/e825.ml
+35
lib/rules/e825.ml
···
1
+
(** E825: Interop test uses CSV traces but dune lacks csvt dependency *)
2
+
3
+
type payload = { dir : string }
4
+
5
+
let check (ctx : Context.project) =
6
+
let dirs = Interop.find_oracle_dirs ctx.project_root in
7
+
List.filter_map
8
+
(fun (d : Interop.oracle_dir) ->
9
+
if d.has_traces && d.has_dune then
10
+
let traces = Filename.concat d.path "traces" in
11
+
let has_csv =
12
+
try
13
+
Sys.readdir traces |> Array.to_list
14
+
|> List.exists (fun f -> Filename.check_suffix f ".csv")
15
+
with Sys_error _ -> false
16
+
in
17
+
if has_csv then
18
+
let dune = Interop.dune_content d.path in
19
+
if not (Astring.String.is_infix ~affix:"csvt" dune) then
20
+
Some (Issue.v { dir = d.path })
21
+
else None
22
+
else None
23
+
else None)
24
+
dirs
25
+
26
+
let pp ppf { dir } =
27
+
Fmt.pf ppf "Interop test %s has CSV traces but dune lacks csvt dependency" dir
28
+
29
+
let rule =
30
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Rule.v ~code:"E825" ~title:"Missing csvt dependency" ~category:Interop_testing
31
+
~hint:
32
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"Interop tests with CSV traces should use csvt for parsing. Add csvt to \
33
+
the (libraries ...) in the dune file and use Csvt.decode_file with a \
34
+
Row codec."
35
+
~examples:[] ~pp (Project check)
+44
lib/rules/e835.ml
+44
lib/rules/e835.ml
···
1
+
(** E835: pip install --break-system-packages in interop script *)
2
+
3
+
type payload = { dir : string; file : string }
4
+
5
+
let check (ctx : Context.project) =
6
+
let dirs = Interop.find_oracle_dirs ctx.project_root in
7
+
List.filter_map
8
+
(fun (d : Interop.oracle_dir) ->
9
+
let scripts = Filename.concat d.path "scripts" in
10
+
if not (Sys.file_exists scripts) then None
11
+
else
12
+
let files =
13
+
try Sys.readdir scripts |> Array.to_list with Sys_error _ -> []
14
+
in
15
+
let bad =
16
+
List.filter_map
17
+
(fun f ->
18
+
if Filename.check_suffix f ".sh" || Filename.check_suffix f ".py"
19
+
then
20
+
let content = Interop.read_file (Filename.concat scripts f) in
21
+
if
22
+
Astring.String.is_infix ~affix:"--break-system-packages"
23
+
content
24
+
then Some f
25
+
else None
26
+
else None)
27
+
files
28
+
in
29
+
match bad with
30
+
| [] -> None
31
+
| file :: _ -> Some (Issue.v { dir = d.path; file }))
32
+
dirs
33
+
34
+
let pp ppf { dir; file } =
35
+
Fmt.pf ppf "%s/scripts/%s uses --break-system-packages" dir file
36
+
37
+
let rule =
38
+
Rule.v ~code:"E835" ~title:"pip install --break-system-packages"
39
+
~category:Interop_testing
40
+
~hint:
41
+
"Python deps must live in a venv. Never use pip install \
42
+
--break-system-packages. The generate.sh wrapper should create/reuse a \
43
+
venv automatically."
44
+
~examples:[] ~pp (Project check)