fix(kt): resolve Gradle executables before wrapping them

.github/justfile

@@ -59,6 +59,7 @@ test:
     bun test sh/gh/ffi.test.ts sh/gh/cpp.test.ts sh/gh/publish.test.ts
     python3 sh/rs/package-rename.test.py
     python3 sh/dart/build.test.py
+    python3 sh/kt/gradle.test.py
     python3 sh/rs/select.test.py
     python3 sh/rs/config.test.py
     python3 sh/js/workspace.test.py

sh/kt/bench.sh

@@ -9,6 +9,13 @@ SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 KT_DIR="$(cd "$SCRIPT_DIR/../../kt" && pwd)"
 export MOQ_BENCH_DIR="${MOQ_BENCH_DIR:-$KT_DIR/../target/bench/ffi}"
 
+# `type -P` resolves only executables, so an inherited shell function named gradle cannot stand in for Gradle.
+gradle_name="${GRADLE_CMD:-gradle}"
+GRADLE_CMD="$(type -P "$gradle_name")" || {
+    echo "kt bench: Gradle executable '$gradle_name' not found; run 'nix develop'" >&2
+    exit 1
+}
+
 MOQ_FFI_PROFILE=release bash "$SCRIPT_DIR/generate.sh"
-gradle -p "$KT_DIR" -Pmoqffi.version=0.0.0-dev :moq:jvmTest --tests dev.moq.FfiBench --rerun
+"$GRADLE_CMD" -p "$KT_DIR" -Pmoqffi.version=0.0.0-dev :moq:jvmTest --tests dev.moq.FfiBench --rerun
 echo "kt bench: wrote $MOQ_BENCH_DIR/kotlin.json"

sh/kt/check.sh

@@ -28,9 +28,11 @@ if ! command -v java >/dev/null 2>&1; then
     exit 1
 fi
 
-GRADLE_CMD="${GRADLE_CMD:-$(command -v gradle || true)}"
-if [[ -z "$GRADLE_CMD" ]]; then
-    echo "kt check: gradle not on PATH; run 'nix develop' or use 'just kt generate' to only regenerate bindings" >&2
+# `type -P` resolves only executables, so an inherited shell function named gradle can neither
+# stand in for Gradle nor make the gradle() wrapper below call itself.
+gradle_name="${GRADLE_CMD:-gradle}"
+if ! GRADLE_CMD="$(type -P "$gradle_name")"; then
+    echo "kt check: Gradle executable '$gradle_name' not found; run 'nix develop' or use 'just kt generate' to only regenerate bindings" >&2
     exit 1
 fi
 

sh/kt/gradle.test.py

@@ -0,0 +1,143 @@
+"""Kotlin runners select executables even when the shell exports Gradle functions."""
+
+import json
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[2]
+BASH = shutil.which("bash")
+RUNNERS = ("check", "package", "bench")
+
+
+class GradleTest(unittest.TestCase):
+    def setUp(self):
+        scratch = ROOT / ".tmp"
+        scratch.mkdir(exist_ok=True)
+        self.directory = tempfile.TemporaryDirectory(dir=scratch)
+        self.addCleanup(self.directory.cleanup)
+        self.root = Path(self.directory.name)
+        self.tools = self.root / "tools"
+        self.tools.mkdir()
+        self.calls = self.root / "calls.jsonl"
+        for name in ("bash", "dirname", "mkdir", "rm", "cp"):
+            (self.tools / name).symlink_to(shutil.which(name))
+        (self.tools / "python3").symlink_to(sys.executable)
+        self.write("tools/java", "exit 0\n")
+        for name in (f"{runner}.sh" for runner in RUNNERS):
+            target = self.root / "sh/kt" / name
+            target.parent.mkdir(parents=True, exist_ok=True)
+            shutil.copy(ROOT / "sh/kt" / name, target)
+        for name in ("format.sh", "generate.sh"):
+            self.write(f"sh/kt/{name}", "exit 0\n")
+        self.write("doc/lib/samples.sh", "exit 0\n")
+        (self.root / "sh/kt/check-poms.py").write_text("")
+        (self.root / "kt/moq/src/jvmAndAndroidTest/kotlin/dev/moq/docs").mkdir(parents=True)
+        source = self.root / "bindings/uniffi/moq/moq.kt"
+        source.parent.mkdir(parents=True)
+        source.write_text("")
+        self.gradle("gradle")
+        self.gradle("custom-gradle")
+
+    def write(self, name, source):
+        target = self.root / name
+        target.parent.mkdir(parents=True, exist_ok=True)
+        target.write_text(f"#!{BASH}\n{source}")
+        target.chmod(0o755)
+
+    def gradle(self, name):
+        target = self.tools / name
+        target.write_text(
+            f"#!{sys.executable}\n"
+            "import json, os, sys\n"
+            'with open(os.environ["GRADLE_CALLS"], "a") as output:\n'
+            "    output.write(json.dumps({\n"
+            '        "executable": sys.argv[0], "args": sys.argv[1:],\n'
+            '        "runner_keys": [key for key in os.environ\n'
+            '                        if key.startswith(("ACTIONS_", "GITHUB_", "RUNNER_"))],\n'
+            '    }) + "\\n")\n'
+            'sys.exit(int(os.environ.get("GRADLE_STATUS", "0")))\n'
+        )
+        target.chmod(0o755)
+
+    def run_script(self, script, **changes):
+        self.calls.unlink(missing_ok=True)
+        # An imported function must never satisfy executable discovery. FUNCNEST
+        # turns a recursive wrapper into a deterministic failure in the fixture.
+        env = {
+            "PATH": str(self.tools),
+            "HOME": str(self.root),
+            "LOCAL_SUPERVISED": "1",
+            "BASH_ENV": os.devnull,
+            "BASH_FUNC_gradle%%": "() { echo 'inherited function called' >&2; return 99; }",
+            "FUNCNEST": "10",
+            "GRADLE_CALLS": str(self.calls),
+            "ACTIONS_TEST": "fixture",
+            "GITHUB_TEST": "fixture",
+            "RUNNER_TEST": "fixture",
+            **changes,
+        }
+        args = [BASH, f"sh/kt/{script}.sh"]
+        if script == "package":
+            args += ["--version", "0.0.0-dev", "--lib-dir", "libs", "--bindings-dir", "bindings", "--output", "dist"]
+        return subprocess.run(args, cwd=self.root, env=env, text=True, capture_output=True)
+
+    def recorded(self):
+        return [json.loads(line) for line in self.calls.read_text().splitlines()]
+
+    def test_path_executable_wins_over_exported_function(self):
+        first = {"check": ":moq:jvmTest", "package": ":moq-ffi:assemble", "bench": "dev.moq.FfiBench"}
+        for script in RUNNERS:
+            for override in ({}, {"GRADLE_CMD": "gradle"}):
+                with self.subTest(script=script, override=override):
+                    result = self.run_script(script, **override)
+                    self.assertEqual(result.returncode, 0, result.stderr)
+                    calls = self.recorded()
+                    self.assertEqual(len(calls), 2 if script == "check" else 1)
+                    self.assertTrue(all(Path(call["executable"]) == self.tools / "gradle" for call in calls))
+                    self.assertIn(first[script], calls[0]["args"])
+                    if script == "check":
+                        self.assertTrue(all(call["runner_keys"] == [] for call in calls))
+                        self.assertIn(":moq:generatePomFileForJvmPublication", calls[1]["args"])
+
+    def test_explicit_executable_is_preserved(self):
+        for script in RUNNERS:
+            for override in ("custom-gradle", "tools/custom-gradle", str(self.tools / "custom-gradle")):
+                with self.subTest(script=script, override=override):
+                    result = self.run_script(script, GRADLE_CMD=override)
+                    self.assertEqual(result.returncode, 0, result.stderr)
+                    self.assertTrue(all(Path(call["executable"]).name == "custom-gradle" for call in self.recorded()))
+
+    def test_function_without_executable_is_refused(self):
+        (self.tools / "gradle").unlink()
+        for script in RUNNERS:
+            with self.subTest(script=script):
+                result = self.run_script(script)
+                self.assertEqual(result.returncode, 1, result.stderr)
+                self.assertIn("Gradle executable 'gradle' not found", result.stderr)
+                self.assertNotIn("inherited function called", result.stderr)
+                self.assertFalse(self.calls.exists())
+
+    def test_missing_override_is_named(self):
+        for script in RUNNERS:
+            with self.subTest(script=script):
+                result = self.run_script(script, GRADLE_CMD="tools/missing-gradle")
+                self.assertEqual(result.returncode, 1, result.stderr)
+                self.assertIn("Gradle executable 'tools/missing-gradle' not found", result.stderr)
+                self.assertFalse(self.calls.exists())
+
+    def test_gradle_failure_stops_the_runner(self):
+        for script in RUNNERS:
+            with self.subTest(script=script):
+                result = self.run_script(script, GRADLE_STATUS="7")
+                self.assertEqual(result.returncode, 7, result.stderr)
+                self.assertEqual(len(self.recorded()), 1)
+                self.assertNotIn("kt bench: wrote", result.stdout)
+
+
+if __name__ == "__main__":
+    unittest.main()

sh/kt/package.sh

@@ -173,9 +173,10 @@ if [[ "$HAVE_ANDROID_LIBS" == true ]]; then
     GRADLE_ARGS+=("-Pandroid.enabled=true")
 fi
 
-GRADLE_CMD="${GRADLE_CMD:-$(command -v gradle || true)}"
-[[ -n "$GRADLE_CMD" ]] || {
-    echo "Error: gradle not on PATH" >&2
+# `type -P` resolves only executables, so an inherited shell function named gradle cannot stand in for Gradle.
+gradle_name="${GRADLE_CMD:-gradle}"
+GRADLE_CMD="$(type -P "$gradle_name")" || {
+    echo "Error: Gradle executable '$gradle_name' not found" >&2
     exit 1
 }