feat(phoenix): Respond to exit status codes

- Detect exit status of Puter apps, now that that's available.
- Store the exit status of each pipeline.
- Display a message when the exit status was non-zero.

That message is temporary, until we have a better way of displaying or
querying it, such as the `$?` shell variable.

packages/phoenix/src/ansi-shell/ANSIShell.js

@@ -160,6 +160,7 @@ export class ANSIShell extends EventTarget {
             }
             this.ctx.externs.out.write('error: ' + e.message + '\n');
             console.log(e);
+            this.ctx.locals.exit = -1;
             return;
         }
     }
@@ -225,6 +226,13 @@ export class ANSIShell extends EventTarget {
         const pipeline = await Pipeline.createFromAST(executionCtx, ast);
         
         await pipeline.execute(executionCtx);
+
+        // Store exit code for the next pipeline
+        // TODO: This feels like a hacky way of doing this.
+        this.ctx.locals.exit = executionCtx.locals.exit;
+        if ( this.ctx.locals.exit ) {
+            this.ctx.externs.out.write(`Exited with code ${this.ctx.locals.exit}\n`);
+        }
     }
 
     expandPromptString (str) {

packages/phoenix/src/ansi-shell/pipeline/Pipeline.js

@@ -247,14 +247,14 @@ export class PreparedCommand {
         if ( ! ctx.cmdExecState.valid ) {
             ctx.locals.exit = -1;
             await ctx.externs.out.close();
-            return;
+            return 1;
         }
 
         if ( ctx.cmdExecState.printHelpAndExit ) {
             ctx.locals.exit = 0;
             await printUsage(command, ctx.externs.out, ctx.vars);
             await ctx.externs.out.close();
-            return;
+            return 0;
         }
 
         let execute = command.execute.bind(command);
@@ -291,13 +291,14 @@ export class PreparedCommand {
                     command.name + ': ' +
                     e.message + '\x1B[0m\n'
                 );
+                exit_code = -1;
             } else {
                 await ctx.externs.err.write(
                     '\x1B[31;1m' +
                     command.name + ': ' +
                     e.toString() + '\x1B[0m\n'
                 );
-                ctx.locals.exit = -1;
+                exit_code = -1;
             }
             if ( ! (e instanceof Exit) ) console.error(e);
         }
@@ -316,6 +317,8 @@ export class PreparedCommand {
 
             await filesystem.write(path, outputMemWriters[i].getAsBlob());
         }
+
+        return exit_code;
     }
 }
 
@@ -348,7 +351,7 @@ export class Pipeline {
         const valve = new Coupler(nextIn, pipeline_input_pipe.in);
         nextIn = pipeline_input_pipe.out;
 
-        // TOOD: this will eventually defer piping of certain
+        // TODO: this will eventually defer piping of certain
         //       sub-pipelines to the Puter Shell.
 
         for ( let i=0 ; i < preparedCommands.length ; i++ ) {
@@ -381,9 +384,11 @@ export class Pipeline {
             const command = preparedCommands[i];
             commandPromises.push(command.execute());
         }
-        await Promise.all(commandPromises);
+        const results = await Promise.all(commandPromises);
+        // TODO: Consider what to do about intermediate exit codes
+        ctx.locals.exit = results[results.length-1];
         await coupler.isDone;
 
         valve.close();
     }
-}
+}

packages/phoenix/src/puter-shell/providers/PuterAppCommandProvider.js

@@ -57,9 +57,12 @@ export class PuterAppCommandProvider {
 
                 // Wait for app to close.
                 const app_close_promise = new Promise((resolve, reject) => {
-                    child.on('close', () => {
-                        // TODO: Exit codes for apps
-                        resolve({ done: true });
+                    child.on('close', (data) => {
+                        if ((data.statusCode ?? 0) != 0) {
+                            reject(new Exit(data.statusCode));
+                        } else {
+                            resolve({ done: true });
+                        }
                     });
                 });