Test cases

src/sysinfo.rs

@@ -7,11 +7,12 @@ use crate::procfs;
 use crate::procfsapi;
 use crate::util;
 
-use std::io::{self, Write};
+use std::io;
 
 pub fn show_system(timestamp: &str) {
     let fs = procfsapi::RealFS::new();
-    match do_show_system(&fs, timestamp) {
+    let mut writer = io::stdout();
+    match do_show_system(&mut writer, &fs, timestamp) {
         Ok(_) => {}
         Err(e) => {
             log::error!("sysinfo failed: {e}");
@@ -21,7 +22,7 @@ pub fn show_system(timestamp: &str) {
 
 const GIB: usize = 1024 * 1024 * 1024;
 
-fn do_show_system(fs: &dyn procfsapi::ProcfsAPI, timestamp: &str) -> Result<(), String> {
+fn do_show_system(writer: &mut dyn io::Write, fs: &dyn procfsapi::ProcfsAPI, timestamp: &str) -> Result<(), String> {
     let (model, sockets, cores_per_socket, threads_per_core) = procfs::get_cpu_info(fs)?;
     let mem_by = procfs::get_memtotal_kib(fs)? * 1024;
     let mem_gib = (mem_by as f64 / GIB as f64).round() as i64;
@@ -93,7 +94,13 @@ fn do_show_system(fs: &dyn procfsapi::ProcfsAPI, timestamp: &str) -> Result<(),
 }}
 "#);
 
-    let _ = io::stdout().write(s.as_bytes());
-    let _ = io::stdout().flush();
+    // Ignore I/O errors.
+
+    let _ = writer.write(s.as_bytes());
+    let _ = writer.flush();
     Ok(())
 }
+
+// Currently the test for do_show_system() is whitebox, see ../tests.  The reason for this is partly
+// that not all the system interfaces used by that function are virtualized at this time, and partly
+// that we only care that the output syntax looks right.

src/util.rs

@@ -102,3 +102,14 @@ pub fn json_quote(s: &str) -> String {
     }
     t
 }
+
+#[test]
+pub fn json_quote_test() {
+    assert!(&json_quote("abcde") == "abcde");
+    assert!(&json_quote(r#"abc\de"#) == r#"abc\\de"#);
+    assert!(&json_quote(r#"abc"de"#) == r#"abc\"de"#);
+    assert!(&json_quote("abc\nde") == r#"abc\nde"#);
+    assert!(&json_quote("abc\rde") == r#"abc\rde"#);
+    assert!(&json_quote("abc	de") == r#"abc\tde"#);
+    assert!(&json_quote("abc\u{0008}de") == r#"abc de"#);
+}

tests/sysinfo-syntax.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+#
+# Check that sysinfo produces properly formatted JSON.
+# Requirement: the `jq` utility.
+
+set -e
+( cd .. ; cargo build )
+if [[ $(command -v jq) == "" ]]; then
+    echo "Install jq first"
+    exit 1
+fi
+output=$(../target/debug/sonar sysinfo)
+jq . <<< $output > /dev/null