Fix parsing larger chunks of input

resources/test/input1.txt

@@ -0,0 +1,45 @@
+00.000*kW)
+1-0:62.7.0(00.000*kW)
+0-1:24.1.0(003)
+0-1:96.1.0(4730303839353635363131313938373233)
+0-1:24.2.1(231026204004S)(00004.381*m3)
+!BAD0
+/ISK5\2M550T-1013
+
+1-3:0.2.8(50)
+0-0:1.0.0(231026204015S)
+0-0:96.1.1(4530303534303038353539313239303233)
+1-0:1.8.1(000032.159*kWh)
+1-0:1.8.2(000002.167*kWh)
+1-0:2.8.1(000002.376*kWh)
+1-0:2.8.2(000000.000*kWh)
+0-0:96.14.0(0002)
+1-0:1.7.0(00.302*kW)
+1-0:2.7.0(00.000*kW)
+0-0:96.7.21(00005)
+0-0:96.7.9(00003)
+1-0:99.97.0(1)(0-0:96.7.19)(230114121128W)(0000000324*s)
+1-0:32.32.0(00000)
+1-0:52.32.0(00000)
+1-0:72.32.0(00000)
+1-0:32.36.0(00003)
+1-0:52.36.0(00003)
+1-0:72.36.0(00003)
+0-0:96.13.0()
+1-0:32.7.0(234.3*V)
+1-0:52.7.0(235.6*V)
+1-0:72.7.0(230.8*V)
+1-0:31.7.0(001*A)
+1-0:51.7.0(000*A)
+1-0:71.7.0(000*A)
+1-0:21.7.0(00.250*kW)
+1-0:41.7.0(00.042*kW)
+1-0:61.7.0(00.000*kW)
+1-0:22.7.0(00.000*kW)
+1-0:42.7.0(00.000*kW)
+1-0:62.7.0(00.000*kW)
+0-1:24.1.0(003)
+0-1:96.1.0(4730303839353635363131313938373233)
+0-1:24.2.1(231026204004S)(00004.381*m3)
+!3812
+/ISK5\2M550T-1013

resources/test/output1.txt

@@ -0,0 +1,38 @@
+/ISK5\2M550T-1013
+
+1-3:0.2.8(50)
+0-0:1.0.0(231026204015S)
+0-0:96.1.1(4530303534303038353539313239303233)
+1-0:1.8.1(000032.159*kWh)
+1-0:1.8.2(000002.167*kWh)
+1-0:2.8.1(000002.376*kWh)
+1-0:2.8.2(000000.000*kWh)
+0-0:96.14.0(0002)
+1-0:1.7.0(00.302*kW)
+1-0:2.7.0(00.000*kW)
+0-0:96.7.21(00005)
+0-0:96.7.9(00003)
+1-0:99.97.0(1)(0-0:96.7.19)(230114121128W)(0000000324*s)
+1-0:32.32.0(00000)
+1-0:52.32.0(00000)
+1-0:72.32.0(00000)
+1-0:32.36.0(00003)
+1-0:52.36.0(00003)
+1-0:72.36.0(00003)
+0-0:96.13.0()
+1-0:32.7.0(234.3*V)
+1-0:52.7.0(235.6*V)
+1-0:72.7.0(230.8*V)
+1-0:31.7.0(001*A)
+1-0:51.7.0(000*A)
+1-0:71.7.0(000*A)
+1-0:21.7.0(00.250*kW)
+1-0:41.7.0(00.042*kW)
+1-0:61.7.0(00.000*kW)
+1-0:22.7.0(00.000*kW)
+1-0:42.7.0(00.000*kW)
+1-0:62.7.0(00.000*kW)
+0-1:24.1.0(003)
+0-1:96.1.0(4730303839353635363131313938373233)
+0-1:24.2.1(231026204004S)(00004.381*m3)
+!3812

src/dsmr/reader.rs

@@ -2,8 +2,10 @@ use super::settings;
 use super::settings::ParityBitSetting;
 
 use std::borrow::Cow;
+use std::fs;
 use std::io::BufRead;
 use std::io::BufReader;
+use std::path::PathBuf;
 use std::str;
 use std::time::Duration;
 
@@ -14,10 +16,11 @@ fn find_start_of_telegram(buffer: &str) -> Option<usize> {
 fn find_end_of_telegram(buffer: &str, from: usize) -> Option<usize> {
     match buffer[from..].find('!') {
         Some(excl_mark) => {
+            let remainder = &buffer[(from + excl_mark + 1)..];
             // Not all meters send the checksum; some simply have a last line with just '!'
-            match buffer[(excl_mark + 1)..].find('\n') {
+            match remainder.find('\n') {
                 Some(line_end) => {
-                    let end = excl_mark + line_end + 1;
+                    let end = from + excl_mark + line_end + 1;
                     log::trace!(
                         "Exclamation mark with line ending found at index {}, returning index {}",
                         excl_mark,
@@ -252,4 +255,27 @@ mod tests {
         );
         assert_eq!(result, "\r\n/ISk5\\2MT382-1000");
     }
+
+    #[test]
+    fn eat_complete_telegram() {
+        let mut input = read_test_resource("input1.txt".into());
+        let mut consumer = TestConsumer::new();
+
+        let _result = eat_telegrams(&mut input, &mut consumer);
+
+        assert_eq!(consumer.invoked, true);
+        assert_eq!(consumer.telegram, read_test_resource("output1.txt".into()),);
+    }
+
+    fn read_test_resource(path: PathBuf) -> String {
+        let mut test_file = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+        test_file.push("resources/test/");
+        test_file.push(path);
+
+        let mut binding = fs::read_to_string(test_file).expect("Failed to read file");
+        let text = binding.as_mut_str();
+        return String::from(text);
+
+        // return fs::read_to_string(test_file).expect("Failed to read file").as_mut_str();
+    }
 }