More tests for version.extract_version_number

Justfile

@@ -1,5 +1,10 @@
 build:
 	@dune build
 
+test:
+	@dune test -f
+	@bisect-ppx-report html
+	@bisect-ppx-report summary --per-file
+
 fmt:
 	@dune build @fmt --auto-promote

lib/flake_env__versions.re

@@ -30,23 +30,27 @@ let compare = (a, b) => {
   }
 }
 
-let extract_version_number = (cmd) => {
+let extract_version_number = cmd => {
   switch (Util.run_process(cmd, ["--version"])) {
-  | (Ok(), stdout)  when String.length(stdout) > 0 => {
-      let substrings = Re.exec(semver_re, stdout);
+  | (Ok (), stdout) when String.length(stdout) > 0 =>
+    switch (Re.exec(semver_re, stdout)) {
+    | exception Stdlib.Not_found =>
+      Error(
+        Printf.sprintf(
+          "Stdout did not contain a version number for `%s --version`",
+          cmd,
+        ),
+      )
+    | substrings =>
       let groups = Re.Group.all(substrings);
-      if ((groups |> Array.length) == 4) {
-        Ok({
-          major: groups[1] |> int_of_string,
-          minor: groups[2] |> int_of_string,
-          point: groups[3] |> int_of_string
-        })
-      } else {
-        Error(Printf.sprintf("Stdout did not contain a version number for `%s --version`", cmd))
-      }
+      Ok({
+        major: groups[1] |> int_of_string,
+        minor: groups[2] |> int_of_string,
+        point: groups[3] |> int_of_string,
+      });
     }
-    | _ => Error(Printf.sprintf("Failed executing '%s'\n", cmd))
-  }
+  | _ => Error(Printf.sprintf("Failed executing '%s'", cmd))
+  };
 };
 
 let is_new_enough = (cur, needed) => {

tests/dune

@@ -3,7 +3,7 @@
     flake_env_test_versions
     flake_env_test_watches
     flake_env_test_util)
-  (deps spit_version.sh)
+  (deps spit_version.sh spit_gibberish.sh)
   (libraries
     lib
     alcotest

tests/flake_env_test_versions.re

@@ -103,8 +103,18 @@ let test_extract_version_number_success = () => {
   check_version("Versions", Ok(Versions.init(1, 1, 1)), result);
 };
 
+let test_extract_version_number_no_version = () => {
+  let result = Versions.extract_version_number("../tests/spit_gibberish.sh");
+  check_version("Versions", Error("Stdout did not contain a version number for `../tests/spit_gibberish.sh --version`"), result);
+};
+
+let test_extract_version_number_nonexistent = () => {
+  let result = Versions.extract_version_number("nonexistent.sh");
+  check_version("Versions", Error("Failed executing 'nonexistent.sh'"), result);
+};
+
+
 // TODO: Test:
-// * extract_version_number: impure, don't know how to get a concrete version number to test against
 // * preflight_versions? impure, but m
 let () =
   Alcotest.(
@@ -167,6 +177,8 @@ let () =
           "extract_version_number",
           [
             test_case("success", `Quick, test_extract_version_number_success),
+            test_case("no version number", `Quick, test_extract_version_number_no_version),
+            test_case("missing binary", `Quick, test_extract_version_number_nonexistent),
           ],
         ),
       ],

tests/spit_gibberish.sh

@@ -0,0 +1,3 @@
+#!/usr/bin/env sh
+
+echo "sdlfkjdsfweiojlsjslfj.dofiwoksdj/sfowiefjw0";