fix: support specifiers in ExecStart= (Resolves #529)

src/main/kotlin/net/sjrx/intellij/plugins/systemdunitfiles/semanticdata/optionvalues/ExecOptionValue.kt

@@ -51,8 +51,15 @@ class ExecOptionValue : OptionValueInformation {
     get() = VALIDATOR_NAME
 
   companion object {
-    // Used to check whether or not there is a problem.
-    private val ABSOLUTE_PATH_REGEX = Pattern.compile("^\\s*(?:[+@:!-]|!!)*\\s*[\\/]")
+    // Specifiers that systemd's unit_path_printf() expands to an absolute filesystem path. A command whose first
+    // token begins with one of these (e.g. ExecStart=%h/bin/foo) resolves to an absolute path, so it must not be
+    // flagged by the "use an absolute path" recommendation below. Text/name specifiers (%i, %n, %H, ...) are
+    // deliberately excluded: they do not guarantee an absolute path. See src/core/unit-printf.c in systemd.
+    private const val ABSOLUTE_PATH_SPECIFIERS = "hsCdDELStTVyYf"
+
+    // Used to check whether or not there is a problem. A value is considered absolute when, after the optional exec
+    // prefixes (+ @ : ! -), it starts with '/' or with a specifier that expands to an absolute path.
+    private val ABSOLUTE_PATH_REGEX = Pattern.compile("^\\s*(?:[+@:!-]|!!)*\\s*(?:[\\/]|%[$ABSOLUTE_PATH_SPECIFIERS])")
 
     // Used to determine what to highlight (we want to avoid highlighting valid prefixes).
     private val RELATIVE_PATH_REGEX = Pattern.compile("^\\s*(?:[+@:!-]+)?([^\\/\\s]\\S*)\\s*")

src/test/kotlin/net/sjrx/intellij/plugins/systemdunitfiles/inspections/InvalidValueInspectionForExecOptionsTest.kt

@@ -338,4 +338,154 @@ class InvalidValueInspectionForExecOptionsTest : AbstractUnitFileTest() {
     assertStringContains("an absolute path", info!!.description)
     TestCase.assertEquals("docker-compose", info.text)
   }
+
+  fun testNoWarningWhenUsingHomeDirectorySpecifier() {
+    // Regression test for GitHub issue #529: %h is a valid systemd specifier that expands to the user's home
+    // directory (an absolute path), so ExecStart=%h/... must not be flagged.
+    // Fixture Setup
+    val file = """
+           [Service]
+           ExecStart=%h/path/to/executable
+
+           """.trimIndent()
+
+
+    // Execute SUT
+    setupFileInEditor("file.service", file)
+    enableInspection(InvalidValueInspection::class.java)
+    val highlights = myFixture.doHighlighting()
+
+    // Verification
+    assertSize(0, highlights)
+  }
+
+  fun testNoWarningWhenUsingRuntimeDirectorySpecifierWithDashPrefix() {
+    // %t expands to the runtime directory root (an absolute path); the dash prefix must not change that.
+    // Fixture Setup
+    val file = """
+           [Service]
+           ExecStart=-%t/foo/bar
+
+           """.trimIndent()
+
+
+    // Execute SUT
+    setupFileInEditor("file.service", file)
+    enableInspection(InvalidValueInspection::class.java)
+    val highlights = myFixture.doHighlighting()
+
+    // Verification
+    assertSize(0, highlights)
+  }
+
+  fun testNoWarningWhenUsingUserShellSpecifier() {
+    // %s expands to the user's shell (an absolute path such as /bin/bash).
+    // Fixture Setup
+    val file = """
+           [Service]
+           ExecStart=%s
+
+           """.trimIndent()
+
+
+    // Execute SUT
+    setupFileInEditor("file.service", file)
+    enableInspection(InvalidValueInspection::class.java)
+    val highlights = myFixture.doHighlighting()
+
+    // Verification
+    assertSize(0, highlights)
+  }
+
+  fun testWeakWarningWhenUsingNonAbsolutePathSpecifier() {
+    // %n (the unit name) is NOT guaranteed to be an absolute path, so the recommendation should still fire.
+    // Fixture Setup
+    val file = """
+           [Service]
+           ExecStart=%n/path/to/executable
+
+           """.trimIndent()
+
+
+    // Execute SUT
+    setupFileInEditor("file.service", file)
+    enableInspection(InvalidValueInspection::class.java)
+    val highlights = myFixture.doHighlighting()
+
+    // Verification
+    assertSize(1, highlights)
+    val info = highlights[0]
+    assertStringContains("an absolute path", info!!.description)
+    TestCase.assertEquals("%n/path/to/executable", info.text)
+  }
+
+  fun testNoWarningForAnyAbsolutePathSpecifier() {
+    // Every specifier that systemd's unit_path_printf() expands to an absolute path must suppress the warning.
+    // These are the full whitelist from ExecOptionValue.ABSOLUTE_PATH_SPECIFIERS (h s C d D E L S t T V y Y f);
+    // keep the two in sync.
+    // Fixture Setup
+    // language="unit file (systemd)"
+    val file = """
+           [Service]
+           ExecStart=%h/path/to/executable
+           ExecStart=%s/path/to/executable
+           ExecStart=%C/path/to/executable
+           ExecStart=%d/path/to/executable
+           ExecStart=%D/path/to/executable
+           ExecStart=%E/path/to/executable
+           ExecStart=%L/path/to/executable
+           ExecStart=%S/path/to/executable
+           ExecStart=%t/path/to/executable
+           ExecStart=%T/path/to/executable
+           ExecStart=%V/path/to/executable
+           ExecStart=%y/path/to/executable
+           ExecStart=%Y/path/to/executable
+           ExecStart=%f/path/to/executable
+
+           """.trimIndent()
+
+
+    // Execute SUT
+    setupFileInEditor("file.service", file)
+    enableInspection(InvalidValueInspection::class.java)
+    val highlights = myFixture.doHighlighting()
+
+    // Verification
+    assertSize(0, highlights)
+  }
+
+  fun testWeakWarningForNonAbsolutePathSpecifiers() {
+    // Specifiers that expand to arbitrary text (names, host/OS facts, user/group) are NOT absolute paths, so the
+    // recommendation must still fire once per line. None of these appears in ExecOptionValue.ABSOLUTE_PATH_SPECIFIERS.
+    // Fixture Setup
+    // language="unit file (systemd)"
+    val file = """
+           [Service]
+           ExecStart=%i/path/to/executable
+           ExecStart=%I/path/to/executable
+           ExecStart=%n/path/to/executable
+           ExecStart=%N/path/to/executable
+           ExecStart=%p/path/to/executable
+           ExecStart=%P/path/to/executable
+           ExecStart=%H/path/to/executable
+           ExecStart=%l/path/to/executable
+           ExecStart=%m/path/to/executable
+           ExecStart=%M/path/to/executable
+           ExecStart=%u/path/to/executable
+           ExecStart=%U/path/to/executable
+           ExecStart=%a/path/to/executable
+           ExecStart=%b/path/to/executable
+           ExecStart=%v/path/to/executable
+
+           """.trimIndent()
+
+
+    // Execute SUT
+    setupFileInEditor("file.service", file)
+    enableInspection(InvalidValueInspection::class.java)
+    val highlights = myFixture.doHighlighting()
+
+    // Verification
+    assertSize(15, highlights)
+  }
 }