Move starting of tasks into a helper struct

tests/common/mod.rs

@@ -5,3 +5,4 @@ pub mod osm;
 pub mod osm_db;
 pub mod osrm_world;
 pub mod scenario_id;
+pub mod task_starter;

tests/common/task_starter.rs

@@ -0,0 +1,65 @@
+use std::{
+    io::{BufRead, BufReader},
+    process::{Child, Command, Stdio},
+};
+
+#[derive(Default)]
+pub struct TaskStarter {
+    ready: bool,
+    command: String,
+    arguments: Vec<String>,
+    child: Option<Child>,
+}
+
+impl TaskStarter {
+    pub fn new(command: &str) -> Self {
+        Self {
+            ready: false,
+            command: command.into(),
+            arguments: Vec::new(),
+            child: None,
+        }
+    }
+    pub fn is_ready(&self) -> bool {
+        self.ready
+    }
+    pub fn arg(&mut self, argument: &str) -> &mut Self {
+        self.arguments.push(argument.into());
+        self
+    }
+
+    pub fn spawn_wait_till_ready(&mut self, ready_token: &str) {
+        // TODO: move the child handling into a convenience struct
+
+        let mut command = &mut Command::new(&self.command);
+        for argument in &self.arguments {
+            command = command.arg(argument);
+        }
+
+        match command.stdout(Stdio::piped()).spawn() {
+            Ok(o) => self.child = Some(o),
+            Err(e) => panic!("cannot spawn task: {e}"),
+        }
+
+        if let Some(output) = &mut self.child.as_mut().unwrap().stdout {
+            // implement with a timeout
+            let mut reader = BufReader::new(output);
+            let mut line = String::new();
+            while let Ok(_count) = reader.read_line(&mut line) {
+                // println!("count: {count} ->{line}");
+                if line.contains(ready_token) {
+                    self.ready = true;
+                    break;
+                }
+            }
+        }
+    }
+}
+
+impl Drop for TaskStarter {
+    fn drop(&mut self) {
+        if let Err(e) = self.child.as_mut().expect("can't access child").kill() {
+            panic!("shutdown failed: {e}");
+        }
+    }
+}

tests/cucumber.rs

@@ -9,15 +9,14 @@ use common::cli_arguments::Args;
 use common::lexicographic_file_walker::LexicographicFileWalker;
 use common::nearest_response::NearestResponse;
 use common::osm::OSMWay;
+use common::task_starter::TaskStarter;
 use core::panic;
 use cucumber::{self, gherkin::Step, given, when, World};
 use futures::{future, FutureExt};
 use geo_types::{point, Point};
-use std::fmt::{format, Display};
 use std::fs::{create_dir_all, File};
-use std::io::{BufRead, BufReader, Read, Write};
+use std::io::{Read, Write};
 use std::path::PathBuf;
-use std::process::{Command, Stdio};
 use std::time::Duration;
 use std::{env, fs};
 use ureq::Agent;
@@ -163,11 +162,6 @@ fn request_nearest(world: &mut OSRMWorld, step: &Step) {
         println!("{cache_path:?} does not exist");
     }
 
-    let routed_path = path.join("build").join("osrm-routed");
-    if !routed_path.exists() {
-        panic!("osrm-routed binary not found");
-    }
-
     // parse query data
     let t = &step.table.as_ref().expect("no query table specified");
     let test_cases: Vec<_> = t
@@ -192,36 +186,18 @@ fn request_nearest(world: &mut OSRMWorld, step: &Step) {
         .collect();
 
     let data_path = cache_path.join(world.scenario_id.to_owned() + ".osrm");
-    println!("{routed_path:?} {}", data_path.to_str().unwrap());
 
-    // TODO: move the child handling into a convenience struct
-    let mut handle = Command::new(routed_path)
-        .arg(data_path.to_str().unwrap())
-        .stdout(Stdio::piped())
-        .spawn();
-
-    let child = match &mut handle {
-        Ok(o) => o,
-        Err(e) => panic!("cannot access handle: {e}"),
-    };
-
-    let mut running = false;
-    if let Some(output) = &mut child.stdout {
-        // implement with a timeout
-        let mut reader = BufReader::new(output);
-        let mut line = String::new();
-        while let Ok(_count) = reader.read_line(&mut line) {
-            // println!("count: {count} ->{line}");
-            if line.contains("running and waiting for requests") {
-                running = true;
-                break;
-            }
-        }
-    }
-    if !running {
-        panic! {"routed not started"}
+    let routed_path = path.join("build").join("osrm-routed");
+    if !routed_path.exists() {
+        panic!("osrm-routed binary not found");
     }
 
+    // TODO: this should not require a temporary and behave like the API of std::process
+    let mut task = TaskStarter::new(routed_path.to_str().unwrap());
+    task.arg(data_path.to_str().unwrap());
+    task.spawn_wait_till_ready("running and waiting for requests");
+    assert!(task.is_ready());
+
     // TODO: move to generic http request handling struct
     let agent: Agent = ureq::AgentBuilder::new()
         .timeout_read(Duration::from_secs(5))
@@ -260,9 +236,9 @@ fn request_nearest(world: &mut OSRMWorld, step: &Step) {
         assert!(approx_equal(result_location.y(), expected_location.y(), 5));
     }
 
-    if let Err(e) = child.kill() {
-        panic!("shutdown failed: {e}");
-    }
+    // if let Err(e) = child.kill() {
+    //     panic!("shutdown failed: {e}");
+    // }
 }
 
 pub fn approx_equal(a: f64, b: f64, dp: u8) -> bool {