bin/vat: add save() to 'shell', load state.json in 'run'

bin/vat

@@ -1,5 +1,7 @@
 #!/usr/bin/env node
 
+const fs = require('fs');
+const path = require('path');
 const process = require('process');
 const repl = require('repl');
 require = require('esm')(module);
@@ -41,6 +43,11 @@ async function main() {
     };
     r.context.run = () => {console.log('run!'); controller.run();};
     r.context.step = () => {console.log('step!'); controller.step();};
+    r.context.save = () => {
+      fs.writeFileSync(path.resolve(basedir, 'state.json'),
+                       JSON.stringify(controller.getState()));
+      console.log('state saved to state.json');
+    };
   }
 }
 

src/controller.js

@@ -10,7 +10,7 @@ import kernelSourceFunc from './bundles/kernel';
 import buildKernelNonSES from './kernel/index';
 import bundleSource from './build-source-bundle';
 
-export function loadBasedir(basedir, state) {
+export function loadBasedir(basedir, stateArg) {
   console.log(`= loading config from basedir ${basedir}`);
   const vatSources = new Map();
   const subs = fs.readdirSync(basedir, { withFileTypes: true });
@@ -37,6 +37,14 @@ export function loadBasedir(basedir, state) {
   } catch (e) {
     bootstrapIndexJS = undefined;
   }
+  let state;
+  const stateFile = path.resolve(basedir, 'state.json');
+  try {
+    const stateData = fs.readFileSync(stateFile);
+    state = JSON.parse(stateData);
+  } catch (e) {
+    state = stateArg;
+  }
   return harden({ vatSources, bootstrapIndexJS, state });
 }
 
@@ -160,9 +168,11 @@ export async function buildVatController(config, withSES = true, argv = []) {
 
   if (config.state) {
     await kernel.loadState(config.state);
+    console.log(`loadState complete`);
   } else if (config.bootstrapIndexJS) {
     // we invoke obj[0].bootstrap with an object that contains 'vats' and
     // 'argv'.
+    console.log(`queueing bootstrap()`);
     kernel.callBootstrap('_bootstrap', JSON.stringify(argv));
   }