provisioner: added invalid shebang test in packer_test

packer_test/provisioner_tests/shell/provisioner_test.go

@@ -65,3 +65,18 @@ func (ts *PackerShellProvisionerTestSuite) TestShebangAsOptionNotInline() {
 		SetArgs("build", "templates/no_shebang_inline_but_as_option.pkr.hcl").
 		Assert(check.MustSucceed())
 }
+
+func (ts *PackerShellProvisionerTestSuite) TestInvalidShebangAsOption() {
+	dir := ts.MakePluginDir()
+	defer dir.Cleanup()
+
+	ts.PackerCommand().UsePluginDir(dir).
+		SetArgs("plugins", "install", "github.com/hashicorp/docker").
+		Assert(check.MustSucceed())
+
+	ts.PackerCommand().UsePluginDir(dir).
+		AddEnv("HOME", os.Getenv("HOME")).
+		AddEnv("PATH", os.Getenv("PATH")).
+		SetArgs("build", "templates/shebang_as_option_invalid.pkr.hcl").
+		Assert(check.MustFail())
+}

packer_test/provisioner_tests/shell/templates/shebang_as_option_invalid.pkr.hcl

@@ -0,0 +1,17 @@
+source "docker" "test" {
+	image = "debian:bookworm"
+	discard = true
+}
+
+build {
+	sources = ["docker.test"]
+
+	provisioner "shell" {
+		inline_shebang = "#!/bin/bash -ex"
+		inline = [
+			"head -1 <\"$0\" | grep -qE '^#!/bin/bash'",
+			"if grep -qE \"^#!/bin/sh\" <\"$0\"; then exit 1; fi",
+			"cat \"$0\""
+		]
+	}
+}