Add Start A Machine In A Specific State as an XState til

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1158 TILs and counting..._
+_1159 TILs and counting..._
 
 ---
 
@@ -1358,6 +1358,7 @@ _1158 TILs and counting..._
 - [Inline Actions vs Actions In Machine Options](xstate/inline-actions-vs-actions-in-machine-options.md)
 - [Make Immediate And Delayed Transitions](xstate/make-immediate-and-delayed-transitions.md)
 - [Simple States And Composite States](xstate/simple-states-and-composite-states.md)
+- [Start A Machine In A Specific State](xstate/start-a-machine-in-a-specific-state.md)
 - [Use An XState Machine With React](xstate/use-an-xstate-machine-with-react.md)
 
 ### YAML

xstate/start-a-machine-in-a-specific-state.md

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+# Start A Machine In A Specific State
+
+For testing (or debugging) purposes, it can be handy to get an XState machine
+running from a specific state.
+
+Let's say a machine has an initial state of `green` and the other states it can
+be in are `yellow` and `red`. And `yellow` has sub-states of `walk` and
+`hurry`.
+
+By default, a machine will start in the specified initial state.
+
+```javascript
+const service = interpret(trafficLightMachine);
+
+service.start();
+
+service.state.value; //=> 'green'
+```
+
+We can tell the traffic light service to start in the `red` state instead.
+
+```javascript
+service.start('red');
+
+service.state.value; //=> 'red'
+```
+
+We can even tell it to start in a sub-state (nested state) of a particular
+state.
+
+```javascript
+service.start({ yellow: 'hurry' });
+
+service.state.value; //=> { yellow: 'hurry' }
+```
+
+[source](https://xstate.js.org/docs/guides/interpretation.html#starting-and-stopping)