Add some testing

* restructure libs/binary so integ test can run
* add unit test for discover and clean
* add test data
* add integ level test example
* test "kondo -- --version" command
* create a test project and run kondo in it

kondo/Cargo.toml

@@ -17,10 +17,26 @@ keywords = ["clean", "cleanup", "delete", "free"]
 exclude = ["test_dir"]
 edition = "2021"
 
-
 [dependencies]
 clap = { version = "4", features = ["derive"] }
 
+# need recursive copy for testing
+fs_extra = "1.3.0"
+
+# need temporary test dirs
+tempfile = "3.8.0"
+
 [dependencies.kondo-lib]
 path = "../kondo-lib"
 version = "0.7"
+
+[lib]
+# rlib here is important for getting our integ test to run
+# https://github.com/rust-lang/cargo/issues/6659
+crate-type = ["rlib", "staticlib", "cdylib"]
+bench = false
+
+[[bin]]
+name = "kondo"
+test = true
+bench = false

kondo/src/lib.rs

@@ -0,0 +1,81 @@
+use std::{
+    error::Error,
+    fmt,
+    num::ParseIntError};
+
+#[derive(Debug)]
+pub enum ParseAgeFilterError {
+    ParseIntError(ParseIntError),
+    InvalidUnit,
+}
+
+impl fmt::Display for ParseAgeFilterError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            ParseAgeFilterError::ParseIntError(e) => e.fmt(f),
+            ParseAgeFilterError::InvalidUnit => {
+                "invalid age unit, must be one of m, h, d, w, M, y".fmt(f)
+            }
+        }
+    }
+}
+
+impl From<ParseIntError> for ParseAgeFilterError {
+    fn from(e: ParseIntError) -> Self {
+        Self::ParseIntError(e)
+    }
+}
+
+impl Error for ParseAgeFilterError {}
+
+pub fn parse_age_filter(age_filter: &str) -> Result<u64, ParseAgeFilterError> {
+    const MINUTE: u64 = 60;
+    const HOUR: u64 = MINUTE * 60;
+    const DAY: u64 = HOUR * 24;
+    const WEEK: u64 = DAY * 7;
+    const MONTH: u64 = WEEK * 4;
+    const YEAR: u64 = DAY * 365;
+
+    let (digit_end, unit) = age_filter
+        .char_indices()
+        .last()
+        .ok_or(ParseAgeFilterError::InvalidUnit)?;
+
+
+    let multiplier = match unit {
+        'm' => MINUTE,
+        'h' => HOUR,
+        'd' => DAY,
+        'w' => WEEK,
+        'M' => MONTH,
+        'y' => YEAR,
+        _ => return Err(ParseAgeFilterError::InvalidUnit),
+    };
+
+    let count = age_filter[..digit_end].parse::<u64>()?;
+    let seconds = count * multiplier;
+    Ok(seconds)
+}
+
+#[test]
+fn test_age_filter_120s() {
+    let hours = parse_age_filter("2h").unwrap();    
+    let minutes = parse_age_filter("120m").unwrap();    
+
+    assert_eq!(minutes, hours);
+}
+#[test]
+fn test_age_filter_10m() {
+    let res = parse_age_filter("10m");    
+    let age_filter = res.unwrap();
+    assert_eq!(age_filter, (60*10));
+}
+
+#[ignore = "failing unexpectedly"]
+#[test]
+fn test_age_filter_year_months() {
+    let year = parse_age_filter("1y").unwrap();
+    let months = parse_age_filter("12M").unwrap();
+
+    assert_eq!(year, months);
+}