Added very basic file verification

tests/ffprobe_media_tests.rs

@@ -1,17 +1,50 @@
+
 extern crate serde_json;
-
-use serde_json::{Result, Value, from_str};
-
+use core::fmt::Debug;
+use serde_json::{Value, from_str};
 use std::fs::File;
 use std::io::Read;
 
-#[test]
-fn test_a() {
-    let mut json_file = File::open("tests/ffprobe_media_results.json").unwrap();
+use bwavfile::WaveReader;
+
+// This seems rickety but we're going with it
+fn assert_match_stream<T>(stream_key: &str, 
+                    other: impl Fn(&mut WaveReader<File>) -> T)
+                    where T: PartialEq + Debug,
+                          T: Into<Value>
+                    {
+
+    let mut json_file = File::open("tests/media_ffprobe_result.json").unwrap();
     let mut s = String::new();
     json_file.read_to_string(&mut s).unwrap();
-    let v: Value = from_str(&mut s).unwrap();
+    if let Value::Array(v) = from_str(&mut s).unwrap() { /* */
+        v.iter()
+            .filter(|value| {
+                !value["format"]["filename"].is_null()
+            })
+            .for_each(|value| {
+                let filen : &str = value["format"]["filename"].as_str().unwrap();
+                let json_value : &Value = &value["streams"][0][stream_key];
+                let mut wavfile = WaveReader::open(filen).unwrap();
+                let wavfile_value: T = other(&mut wavfile);
+                println!("asserting {} for {}",stream_key, filen);
+                assert_eq!(Into::<Value>::into(wavfile_value), *json_value);
 
-    //println!("file list: {:?}", ffprobe_data);
+            })
+    }
+} 
 
+#[test]
+fn test_frame_count() {    
+    assert_match_stream("duration_ts", |w| w.frame_length().unwrap() );
+}
+
+#[test]
+fn test_sample_rate() {
+    assert_match_stream("sample_rate", |w| format!("{}", w.format().unwrap().sample_rate) );
+}
+
+#[test]
+fn test_channel_count() {
+    assert_match_stream("channels", |w| w.format().unwrap().channel_count );
 }