fix: session refactoring with Saad & Allan

api/src/controllers/internal/Session.ts

@@ -1,4 +1,7 @@
 import { Session } from '../../types'
+import { configuration } from '../../../package.json'
+import { promisify } from 'util'
+import { execFile } from 'child_process'
 import { getTmpSessionsFolderPath, generateUniqueFileName } from '../../utils'
 import {
   deleteFolder,
@@ -9,6 +12,9 @@ import {
 } from '@sasjs/utils'
 import path from 'path'
 import { ExecutionController } from './Execution'
+import { date } from 'joi'
+
+const execFilePromise = promisify(execFile)
 
 export class SessionController {
   private sessions: Session[] = []
@@ -34,7 +40,8 @@ export class SessionController {
     const sessionId = generateUniqueFileName(generateTimestamp())
     const sessionFolder = path.join(getTmpSessionsFolderPath(), sessionId)
 
-    const autoExecContent = `data _null_;
+    const autoExecContent = `
+  data _null_;
     /* remove the dummy SYSIN */
     length fname $8;
     rc=filename(fname,getoption('SYSIN') );
@@ -45,12 +52,14 @@ export class SessionController {
     do until ( fileexist(getoption('SYSIN')) or slept>(60*15) );
       slept=slept+sleep(0.01,1);
     end;
+    stop;
   run;
-  EOL`
-
+`
+    // the autoexec file is executed on SAS startup
     const autoExec = path.join(sessionFolder, 'autoexec.sas')
     await createFile(autoExec, autoExecContent)
 
+    // a dummy SYSIN code.sas file is necessary to start SAS
     await createFile(path.join(sessionFolder, 'code.sas'), '')
 
     const creationTimeStamp = sessionId.split('-').pop() as string
@@ -65,17 +74,49 @@ export class SessionController {
         1000
       ).toString(),
       path: sessionFolder,
-      inUse: false
+      inUse: false,
+      completed: false
     }
 
+    // we do not want to leave sessions running forever 
+    // we clean them up after a predefined period, if unused
     this.scheduleSessionDestroy(session)
 
-    this.executionController
-      .execute('', undefined, autoExec, session)
-      .catch(() => {})
+    // create empty code.sas as SAS will not start without a SYSIN
+    const codePath = path.join(session.path, 'code.sas')
+    await createFile(codePath, '')
 
+
+    // this.executionController
+    //   .execute('', undefined, autoExec, session)
+    //   .catch((err) => {console.log(err)})
+    
+
+    // trigger SAS but don't wait for completion - we need to 
+    // update the session array to say that it is currently running
+    // however we also need a promise so that we can update the
+    // session array to say that it has (eventually) finished.
+    const sasLoc = process.sasLoc ?? configuration.sasPath
+    execFilePromise(sasLoc, [
+      '-SYSIN',
+      codePath,
+      '-LOG',
+      path.join(session.path, 'log.log'),
+      '-WORK',
+      session.path,
+      '-AUTOEXEC', 
+      path.join(session.path, 'autoexec.sas'),
+      process.platform === 'win32' ? '-nosplash' : ''
+    ]).then(() => {
+      session.completed=true
+      console.log('session completed', session)
+    }).catch((err) => {})
+
+    // we have a triggered session - add to array
     this.sessions.push(session)
 
+    // SAS has been triggered but we can't use it until 
+    // the autoexec deletes the code.sas file
     await this.waitForSession(session)
 
     return session
@@ -85,8 +126,6 @@ export class SessionController {
     if (await fileExists(path.join(session.path, 'code.sas'))) {
       while (await fileExists(path.join(session.path, 'code.sas'))) {}
 
-      await deleteFile(path.join(session.path, 'log.log'))
-
       session.ready = true
 
       return Promise.resolve(session)
@@ -98,8 +137,10 @@ export class SessionController {
   }
 
   public async deleteSession(session: Session) {
+    // remove the temporary files, to avoid buildup
     await deleteFolder(session.path)
 
+    // remove the session from the session array
     if (session.ready) {
       this.sessions = this.sessions.filter(
         (sess: Session) => sess.id !== session.id