Fix subkeys, write comparison test

3 files changed, 97 insertions, 1 deletions

diff --git a/src/lib.rs b/src/lib.rs
index bd01f59..dc29621 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -14,6 +14,9 @@ use alloc::{format, vec};
 use core::fmt;
 use core::mem::take;
 
+#[cfg(test)]
+mod tests;
+
 /// File and line information
 #[derive(Clone, Debug)]
 pub struct Location {
@@ -635,6 +638,8 @@ impl Configuration {
 	///
 	/// `reader` can be `&str`, `&[u8]`, or anything that implements [`std::io::BufRead`]
 	/// (if the `std` feature is enabled) such as `std::io::BufReader<std::fs::File>`.
+	///
+	/// `filename` is used in error messages.
 	pub fn load<R: Read>(filename: &str, mut reader: R) -> Result<Self> {
 		// avoid big code size by using dyn reference.
 		// the impact on performance is not really important.
@@ -717,7 +722,7 @@ impl Configuration {
 	pub fn subkeys(&self, key: &str) -> impl '_ + Iterator<Item = &str> {
 		let key_dot = format!("{key}.");
 		let start_idx = self.first_subkey_index(key);
-		(start_idx..).map_while(move |i| {
+		(start_idx..self.items.len()).map_while(move |i| {
 			let this_key = &self.items[i].0;
 			let suffix = this_key.strip_prefix(&key_dot)?;
 			Some(suffix.split_once('.').map_or(suffix, |(x, _)| x))
diff --git a/src/tests/mod.rs b/src/tests/mod.rs
new file mode 100644
index 0000000..58cd2b0
--- /dev/null
+++ b/src/tests/mod.rs
@@ -0,0 +1,56 @@
+use crate::Configuration;
+use std::collections::HashSet;
+
+mod parsing;
+
+fn check_configs_equal(
+	cfg1: &Configuration,
+	cfg2: &Configuration,
+) -> Result<(), Box<dyn std::error::Error>> {
+	fn check_configs_equal_at(
+		cfg1: &Configuration,
+		cfg2: &Configuration,
+		prefix: &str,
+	) -> Result<(), Box<dyn std::error::Error>> {
+		let (keys1, keys2): (HashSet<&str>, HashSet<&str>) =
+			if let Some(k) = prefix.strip_suffix('.') {
+				(cfg1.subkeys(k).collect(), cfg2.subkeys(k).collect())
+			} else {
+				(cfg1.keys().collect(), cfg2.keys().collect())
+			};
+		for key in keys1.difference(&keys2) {
+			return Err(format!(
+				"Key {prefix}{key} appears at {}, but not in other configuration",
+				cfg1.location(&format!("{prefix}{key}")).unwrap()
+			)
+			.into());
+		}
+		for key in keys2.difference(&keys1) {
+			return Err(format!(
+				"Key {prefix}{key} appears at {}, but not in other configuration",
+				cfg2.location(&format!("{prefix}{key}")).unwrap()
+			)
+			.into());
+		}
+		for key in &keys1 {
+			let full_key = format!("{prefix}{key}");
+			let val1 = cfg1.get(&full_key);
+			let val2 = cfg2.get(&full_key);
+			if val1 != val2 {
+				return Err(format!(
+					"Mismatch between values for key {full_key}
+    defined as {val1:?} at {},
+but defined as {val2:?} at {}",
+					cfg1.location(&full_key)
+						.map_or("<nowhere>".into(), |x| format!("{x}")),
+					cfg2.location(&full_key)
+						.map_or("<nowhere>".into(), |x| format!("{x}")),
+				)
+				.into());
+			}
+			check_configs_equal_at(cfg1, cfg2, &format!("{full_key}."))?;
+		}
+		Ok(())
+	}
+	check_configs_equal_at(cfg1, cfg2, "")
+}
diff --git a/src/tests/parsing.rs b/src/tests/parsing.rs
new file mode 100644
index 0000000..2e701ed
--- /dev/null
+++ b/src/tests/parsing.rs
@@ -0,0 +1,35 @@
+use crate::Configuration;
+
+static TEST_DIR: &str = "../tests/parsing";
+
+fn single_test(flat_name: &str, complex_name: &str) -> Result<(), Box<dyn std::error::Error>> {
+	let config1 = Configuration::load_path(format!("{TEST_DIR}/{flat_name}"))?;
+	let config2 = Configuration::load_path(format!("{TEST_DIR}/{complex_name}"))?;
+	super::check_configs_equal(&config1, &config2)
+}
+
+fn try_parsing() -> Result<(), Box<dyn std::error::Error>> {
+	let tests = std::fs::read_dir(TEST_DIR).map_err(|e| {
+		format!(
+			"error reading {TEST_DIR}: {e} — try moving pom-rs to inside the main pom repository?"
+		)
+	})?;
+	for test_entry in tests {
+		let filename = test_entry
+			.map_err(|e| format!("error reading tests directory {TEST_DIR}: {e}"))?
+			.file_name()
+			.into_string()
+			.expect("bad UTF-8 in test name (file in {TEST_DIR})");
+		if filename.ends_with(".flat.pom") {
+			single_test(&filename, filename.replace(".flat.pom", ".pom").as_ref())?;
+		}
+	}
+	Ok(())
+}
+
+#[test]
+fn parsing() {
+	if let Err(e) = try_parsing() {
+		panic!("Error: {e}");
+	}
+}