Convert the test simulations to integration tests - making them better examples that only use the public API

Author: ndebuhr

README.md

@@ -58,10 +58,13 @@ npm i sim-rs
 
 Please refer to the documentation at [https://docs.rs/sim](https://docs.rs/sim)
 
-Also, the [test simulations](src/simulator/test_simulations.rs) are a good reference for creating, running, and analyzing simulations with Sim.
+Also, the [test simulations](tests/simulations.rs) are a good reference for creating, running, and analyzing simulations with Sim.
 
 ### Creating Simulations
-Simulation definitions are defined in a declarative YAML or JSON format, and then ingested through `Simulation`'s `post_yaml` or `post_json` constructors.
+
+Rust simulations are created by passing `Model`s and `Connector`s to `Simulation`'s `post` constructor.
+
+WebAssembly simulations are defined in a declarative YAML or JSON format, and then ingested through `WebSimulation`'s `post_yaml` or `post_json` constructors.
 
 Both models and connectors are required to define the simulation.  For descriptions of the pre-built models, see [MODELS.md](MODELS.md) A simple three-model simulation could be defined as:
 
@@ -116,7 +119,7 @@ Analyzing simulations will typically involve some combination of listening to mo
 
 ## Contributing
 
-Issues, feature requests and pull requests are always welcome!
+Issues, feature requests, and pull requests are always welcome!
 
 ## License
 

src/simulator/mod.rs

@@ -25,9 +25,6 @@ use crate::models::{AsModel, Model, ModelMessage};
 use crate::utils;
 use crate::utils::error::SimulationError;
 
-#[cfg(test)]
-mod test_simulations;
-
 /// Connectors are configured to connect models through their ports.  During
 /// simulation, models exchange messages (as per the Discrete Event System
 /// Specification) via these connectors.
@@ -78,6 +75,26 @@ pub struct Message {
 }
 
 impl Message {
+    /// This constructor method builds a `Message`, which is passed between
+    /// simulation models
+    pub fn new(
+        source_id: String,
+        source_port: String,
+        target_id: String,
+        target_port: String,
+        time: f64,
+        content: String,
+    ) -> Self {
+        Self {
+            source_id,
+            source_port,
+            target_id,
+            target_port,
+            time,
+            content,
+        }
+    }
+
     /// This accessor method returns the model ID of a message source.
     pub fn source_id(&self) -> &str {
         &self.source_id