0.3.6: WIP

patch/chrono-0.4.41/tests/dateutils.rs

@@ -0,0 +1,165 @@
+#![cfg(all(unix, feature = "clock", feature = "std"))]
+
+use std::{path, process, thread};
+
+#[cfg(target_os = "linux")]
+use chrono::Days;
+use chrono::{Datelike, Local, NaiveDate, NaiveDateTime, NaiveTime, TimeZone, Timelike};
+
+fn verify_against_date_command_local(path: &'static str, dt: NaiveDateTime) {
+    let output = process::Command::new(path)
+        .arg("-d")
+        .arg(format!("{}-{:02}-{:02} {:02}:05:01", dt.year(), dt.month(), dt.day(), dt.hour()))
+        .arg("+%Y-%m-%d %H:%M:%S %:z")
+        .output()
+        .unwrap();
+
+    let date_command_str = String::from_utf8(output.stdout).unwrap();
+
+    // The below would be preferred. At this stage neither earliest() or latest()
+    // seems to be consistent with the output of the `date` command, so we simply
+    // compare both.
+    // let local = Local
+    //     .with_ymd_and_hms(year, month, day, hour, 5, 1)
+    //     // looks like the "date" command always returns a given time when it is ambiguous
+    //     .earliest();
+
+    // if let Some(local) = local {
+    //     assert_eq!(format!("{}\n", local), date_command_str);
+    // } else {
+    //     // we are in a "Spring forward gap" due to DST, and so date also returns ""
+    //     assert_eq!("", date_command_str);
+    // }
+
+    // This is used while a decision is made whether the `date` output needs to
+    // be exactly matched, or whether MappedLocalTime::Ambiguous should be handled
+    // differently
+
+    let date = NaiveDate::from_ymd_opt(dt.year(), dt.month(), dt.day()).unwrap();
+    match Local.from_local_datetime(&date.and_hms_opt(dt.hour(), 5, 1).unwrap()) {
+        chrono::MappedLocalTime::Ambiguous(a, b) => assert!(
+            format!("{}\n", a) == date_command_str || format!("{}\n", b) == date_command_str
+        ),
+        chrono::MappedLocalTime::Single(a) => {
+            assert_eq!(format!("{}\n", a), date_command_str);
+        }
+        chrono::MappedLocalTime::None => {
+            assert_eq!("", date_command_str);
+        }
+    }
+}
+
+/// path to Unix `date` command. Should work on most Linux and Unixes. Not the
+/// path for MacOS (/bin/date) which uses a different version of `date` with
+/// different arguments (so it won't run which is okay).
+/// for testing only
+#[allow(dead_code)]
+#[cfg(not(target_os = "aix"))]
+const DATE_PATH: &str = "/usr/bin/date";
+#[allow(dead_code)]
+#[cfg(target_os = "aix")]
+const DATE_PATH: &str = "/opt/freeware/bin/date";
+
+#[cfg(test)]
+/// test helper to sanity check the date command behaves as expected
+/// asserts the command succeeded
+fn assert_run_date_version() {
+    // note environment variable `LANG`
+    match std::env::var_os("LANG") {
+        Some(lang) => eprintln!("LANG: {:?}", lang),
+        None => eprintln!("LANG not set"),
+    }
+    let out = process::Command::new(DATE_PATH).arg("--version").output().unwrap();
+    let stdout = String::from_utf8(out.stdout).unwrap();
+    let stderr = String::from_utf8(out.stderr).unwrap();
+    // note the `date` binary version
+    eprintln!("command: {:?} --version\nstdout: {:?}\nstderr: {:?}", DATE_PATH, stdout, stderr);
+    assert!(out.status.success(), "command failed: {:?} --version", DATE_PATH);
+}
+
+#[test]
+fn try_verify_against_date_command() {
+    if !path::Path::new(DATE_PATH).exists() {
+        eprintln!("date command {:?} not found, skipping", DATE_PATH);
+        return;
+    }
+    assert_run_date_version();
+
+    eprintln!(
+        "Run command {:?} for every hour from 1975 to 2077, skipping some years...",
+        DATE_PATH,
+    );
+
+    let mut children = vec![];
+    for year in [1975, 1976, 1977, 2020, 2021, 2022, 2073, 2074, 2075, 2076, 2077].iter() {
+        children.push(thread::spawn(|| {
+            let mut date = NaiveDate::from_ymd_opt(*year, 1, 1).unwrap().and_time(NaiveTime::MIN);
+            let end = NaiveDate::from_ymd_opt(*year + 1, 1, 1).unwrap().and_time(NaiveTime::MIN);
+            while date <= end {
+                verify_against_date_command_local(DATE_PATH, date);
+                date += chrono::TimeDelta::try_hours(1).unwrap();
+            }
+        }));
+    }
+    for child in children {
+        // Wait for the thread to finish. Returns a result.
+        let _ = child.join();
+    }
+}
+
+#[cfg(target_os = "linux")]
+fn verify_against_date_command_format_local(path: &'static str, dt: NaiveDateTime) {
+    let required_format =
+        "d%d D%D F%F H%H I%I j%j k%k l%l m%m M%M q%q S%S T%T u%u U%U w%w W%W X%X y%y Y%Y z%:z";
+    // a%a - depends from localization
+    // A%A - depends from localization
+    // b%b - depends from localization
+    // B%B - depends from localization
+    // h%h - depends from localization
+    // c%c - depends from localization
+    // p%p - depends from localization
+    // r%r - depends from localization
+    // x%x - fails, date is dd/mm/yyyy, chrono is dd/mm/yy, same as %D
+    // Z%Z - too many ways to represent it, will most likely fail
+
+    let output = process::Command::new(path)
+        .env("LANG", "c")
+        .env("LC_ALL", "c")
+        .arg("-d")
+        .arg(format!(
+            "{}-{:02}-{:02} {:02}:{:02}:{:02}",
+            dt.year(),
+            dt.month(),
+            dt.day(),
+            dt.hour(),
+            dt.minute(),
+            dt.second()
+        ))
+        .arg(format!("+{}", required_format))
+        .output()
+        .unwrap();
+
+    let date_command_str = String::from_utf8(output.stdout).unwrap();
+    let date = NaiveDate::from_ymd_opt(dt.year(), dt.month(), dt.day()).unwrap();
+    let ldt = Local
+        .from_local_datetime(&date.and_hms_opt(dt.hour(), dt.minute(), dt.second()).unwrap())
+        .unwrap();
+    let formatted_date = format!("{}\n", ldt.format(required_format));
+    assert_eq!(date_command_str, formatted_date);
+}
+
+#[test]
+#[cfg(target_os = "linux")]
+fn try_verify_against_date_command_format() {
+    if !path::Path::new(DATE_PATH).exists() {
+        eprintln!("date command {:?} not found, skipping", DATE_PATH);
+        return;
+    }
+    assert_run_date_version();
+
+    let mut date = NaiveDate::from_ymd_opt(1970, 1, 1).unwrap().and_hms_opt(12, 11, 13).unwrap();
+    while date.year() < 2008 {
+        verify_against_date_command_format_local(DATE_PATH, date);
+        date = date + Days::new(55);
+    }
+}