fix: major error in batch processing

* a multiple MSH segment is a batch
* moved split and getSegIndex to utils.ts
* updated unit testing for code fixes

__tests__/hl7.build.test.ts

@@ -921,7 +921,7 @@ describe('node hl7 client - builder tests', () => {
           msh_10: 'CONTROL_ID'
         }
       })
-      expect(isBatch(message.toString())).toBe(false)
+      expect(isBatch(message.toString())).toBe(true)
     })
 
     test('...isBatch -should be false', async () => {
@@ -948,10 +948,12 @@ describe('node hl7 client - builder tests', () => {
 
   describe('parse message, batch, and file', () => {
     const hl7_string: string = 'MSH|^~\\&|||||20081231||ADT^A01^ADT_A01|12345||2.7\rEVN||20081231'
+    const hl7_batch_msh_string: string = 'MSH|^~\\&|||||20081231||ADT^A01^ADT_A01|12345||2.7\rEVN||20081231\rMSH|^~\\&|||||20081231||ADT^A01^ADT_A01|12345||2.7\rEVN||20081231'
     const hl7_non_standard: string = 'MSH:-+?*:field2:field3component1-field3component2:field4repeat1+field4repeat2:field5subcomponent1*field5subcomponent2:field6?R?'
     const hl7_batch: string = 'BHS|^~\\&|||||20231208\rMSH|^~\\&|||||20231208||ADT^A01^ADT_A01|CONTROL_ID||2.7\rEVN||20081231\rEVN||20081231\rBTS|1'
     const hl7_batch_non_standard: string = 'BHS:-+?*:::::20231208\rMSH|^~\\&|||||20231208||ADT^A01^ADT_A01|CONTROL_ID||2.7\rEVN||20081231\rEVN||20081231\rBTS|1'
 
+
     test('...verify MSH input', async () => {
       const message = new Message({ text: hl7_string })
 
@@ -1012,6 +1014,16 @@ describe('node hl7 client - builder tests', () => {
         expect(count).toBe(2)
       })
     })
+
+    test('...should be used as a batch', async () => {
+      try {
+        // @ts-expect-error
+        const message = new Message({ text: hl7_batch_msh_string })
+      }catch (err) {
+        expect(err).toEqual(new Error('Multiple MSH segments found. Use Batch.'))
+      }
+    })
+
   })
 
   describe('file tests', () => {

__tests__/hl7.end2end.test.ts

@@ -627,8 +627,12 @@ describe('node hl7 end to end - client', () => {
 
   describe('...send file with two message, get proper ACK', () => {
     let LISTEN_PORT: number
+    let fileName: string
 
-    const hl7_string: string = 'MSH|^~\\&|||||20081231||ADT^A01^ADT_A01|12345|D|2.7\rEVN||20081231\rMSH|^~\\&|||||20081231||ADT^A01^ADT_A01|12345|D|2.7\rEVN||20081231'
+    const hl7_string: string[] = [
+      "MSH|^~\\&|||||20081231||ADT^A01^ADT_A01|12345|D|2.7\rEVN||20081231",
+      "MSH|^~\\&|||||20081231||ADT^A01^ADT_A01|12345|D|2.7\rEVN||20081231"
+    ]
 
     beforeAll(async () => {
       fs.readdir('temp/', (err, files) => {
@@ -642,18 +646,28 @@ describe('node hl7 end to end - client', () => {
 
       await sleep(2)
 
-      const message = new Message({ text: hl7_string, date: '8' })
-      message.toFile('readFileTestMSH', true, 'temp/')
+      const batch = new Batch()
 
-      fs.access('temp/hl7.readFileTestMSH.20081231.hl7', fs.constants.F_OK, (err) => {
+      batch.start()
+
+      for (let i = 0; i < hl7_string.length; i++) {
+        const message = new Message({text: hl7_string[i] })
+        batch.add(message)
+      }
+
+      batch.end()
+
+      fileName = batch.toFile('readFileTestMSH', true, 'temp/')
+
+      fs.access(`temp/${fileName as string}`, fs.constants.F_OK, (err) => {
         if (err == null) {
           // Do something
         }
       })
 
       await (async () => {
         try {
-          await fs.promises.access('temp/hl7.readFileTestMSH.20081231.hl7', fs.constants.F_OK)
+          await fs.promises.access(`temp/${fileName as string}`, fs.constants.F_OK)
           // Do something
         } catch (err) {
           // Handle error
@@ -693,7 +707,7 @@ describe('node hl7 end to end - client', () => {
 
       await expectEvent(OB_ADT, 'client.connect')
 
-      const fileBatch = await OB_ADT.readFile('temp/hl7.readFileTestMSH.20081231.hl7')
+      const fileBatch = await OB_ADT.readFile(`temp/${fileName as string}`)
 
       await OB_ADT.sendMessage(fileBatch)
 

src/builder/batch.ts

@@ -1,6 +1,6 @@
 import { HL7FatalError, HL7ParserError } from '../utils/exception.js'
 import { ClientBuilderOptions, normalizedClientBatchBuilderOptions } from '../utils/normalizedBuilder.js'
-import { createHL7Date } from '../utils/utils.js'
+import { createHL7Date, split } from '../utils/utils.js'
 import { FileBatch } from './fileBatch.js'
 import { HL7Node } from './interface/hL7Node.js'
 import { Message } from './message.js'
@@ -36,7 +36,7 @@ export class Batch extends RootBase {
     this._messagesCount = 0
 
     if (typeof opt.text !== 'undefined' && opt.parsing === true && opt.text !== '') {
-      this._lines = this.split(opt.text).filter(line => line.startsWith('MSH'))
+      this._lines = split(opt.text).filter(line => line.startsWith('MSH'))
     } else {
       this.set('BHS.7', createHL7Date(new Date(), this._opt.date))
     }
@@ -194,7 +194,7 @@ export class Batch extends RootBase {
    * ```
    * You can set an `extension` parameter on Batch to set a custom extension if you don't want to be HL7.
    */
-  toFile (name: string, newLine?: boolean, location?: string, extension: string = 'hl7'): void {
+  toFile (name: string, newLine?: boolean, location?: string, extension: string = 'hl7'): string {
     const fileBatch = new FileBatch({ location, newLine: newLine === true ? '\n' : '', extension })
     fileBatch.start()
 
@@ -210,6 +210,8 @@ export class Batch extends RootBase {
     fileBatch.end()
 
     fileBatch.createFile(name)
+
+    return fileBatch.fileName()
   }
 
   /** @internal */

src/builder/fileBatch.ts

@@ -2,7 +2,7 @@ import fs from 'node:fs'
 import path from 'node:path'
 import { HL7FatalError, HL7ParserError } from '../utils/exception.js'
 import { ClientBuilderFileOptions, normalizedClientFileBuilderOptions } from '../utils/normalizedBuilder.js'
-import { createHL7Date } from '../utils/utils.js'
+import { createHL7Date, split } from '../utils/utils.js'
 import { Batch } from './batch.js'
 import { HL7Node } from './interface/hL7Node.js'
 import { Message } from './message.js'
@@ -44,9 +44,10 @@ export class FileBatch extends RootBase {
     this._opt = opt
     this._batchCount = 0
     this._messagesCount = 0
+    this._fileName = ''
 
     if (typeof opt.text !== 'undefined' && opt.parsing === true && opt.text !== '') {
-      this._lines = this.split(opt.text).filter(line => line.startsWith('MSH'))
+      this._lines = split(opt.text).filter(line => line.startsWith('MSH'))
     } else {
       this.set('FHS.7', createHL7Date(new Date(), this._opt.date))
     }
@@ -130,6 +131,15 @@ export class FileBatch extends RootBase {
     segment.set('1', this._batchCount + this._messagesCount)
   }
 
+  /**
+   * Get File name
+   * @description Get File name going to be created.
+   * @since 1.2.0
+   */
+  fileName (): string {
+    return this._fileName
+  }
+
   /**
    * Get FHS Segment at Path
    * @since 1.0.0

src/builder/message.ts

@@ -1,6 +1,6 @@
-import { HL7FatalError } from '../utils/exception.js'
+import { HL7FatalError, HL7ParserError } from '../utils/exception.js'
 import { ClientBuilderMessageOptions, normalizedClientMessageBuilderOptions } from '../utils/normalizedBuilder.js'
-import { isHL7Number } from '../utils/utils.js'
+import { isHL7Number, split } from '../utils/utils.js'
 import { FileBatch } from './fileBatch.js'
 import { NodeBase } from './modules/nodeBase.js'
 import { RootBase } from './modules/rootBase.js'
@@ -41,6 +41,13 @@ export class Message extends RootBase {
 
     this._opt = opt
 
+    if (typeof opt.text !== 'undefined' && opt.parsing === true && opt.text !== '') {
+      const totalMsh = split(opt.text).filter(line => line.startsWith('MSH'))
+      if (totalMsh.length !== 0 && totalMsh.length !== 1) {
+        throw new HL7ParserError(500, 'Multiple MSH segments found. Use Batch.')
+      }
+    }
+
     if (typeof this._opt.messageHeader !== 'undefined') {
       if (this._opt.specification.checkMSH(this._opt.messageHeader) === true) {
         this._opt.specification.buildMSH(this._opt.messageHeader, this)

src/builder/modules/rootBase.ts

@@ -100,21 +100,6 @@ export class RootBase extends NodeBase {
     })
   }
 
-  /** @internal */
-  split (data: string, segments: string[] = []): string[] {
-    const getSegIndex = [...this._getSegIndexes(['FHS', 'BHS', 'MSH', 'BTS', 'FTS'], data)]
-    getSegIndex.sort((a, b) => parseInt(a) - parseInt(b))
-    for (let i = 0; i < getSegIndex.length; i++) {
-      const start = parseInt(getSegIndex[i])
-      let end = parseInt(getSegIndex[i + 1])
-      if (i + 1 === getSegIndex.length) {
-        end = data.length
-      }
-      segments.push(data.slice(start, end))
-    }
-    return segments
-  }
-
   /** @internal */
   unescape (text: string): string {
     if (text === null) {
@@ -153,26 +138,4 @@ export class RootBase extends NodeBase {
       return ''
     })
   }
-
-  /** @internal */
-  private _getSegIndexes (names: string[], data: string, list: string[] = []): string[] {
-    for (let i = 0; i < names.length; i++) {
-      const regex = new RegExp(`(\\n|\\r|)(${names[i]})\\|`, 'g')
-      let m
-      while ((m = regex.exec(data)) != null) {
-        const s = m[0]
-        if (s.includes('\r\n')) {
-          m.index = m.index + 2
-        } else if (s.includes('\n')) {
-          m.index++
-        } else if (s.includes('\r')) {
-          m.index++
-        }
-        if (m.index !== null) {
-          list.push(m.index.toString())
-        }
-      }
-    }
-    return list
-  }
 }

src/utils/utils.ts

@@ -83,16 +83,17 @@ export const expBackoff = (step: number, high: number, attempts: number, exp = 2
 }
 
 /**
- * Check to see if the message is a Batch (BHS)
+ * Check to see if the message starts with Batch (BHS) header segment.
  * @since 1.0.0
  * @param message
  */
 export const isBatch = (message: string): boolean => {
-  return message.startsWith('BHS')
+  const lines = split(message).filter(line => line.startsWith('MSH')).length > 0 || false
+  return message.startsWith('BHS') || lines
 }
 
 /**
- * Check to see if the message is a File Batch (FHS)
+ * Check to see if the message starts with a a File Batch (FHS) header segment.
  * @param message
  */
 export const isFile = (message: string): boolean => {
@@ -172,3 +173,53 @@ export const randomString = (length = 20): string => {
   }
   return result
 }
+
+/**
+ * Split the message.
+ * @description Split the message into its parts.
+ * @since 1.0.0
+ * @param data
+ * @param segments
+ */
+export const split = (data: string, segments: string[] = []): string[] => {
+  const getSegIndex = [...getSegIndexes(['FHS', 'BHS', 'MSH', 'BTS', 'FTS'], data)]
+  getSegIndex.sort((a, b) => parseInt(a) - parseInt(b))
+  for (let i = 0; i < getSegIndex.length; i++) {
+    const start = parseInt(getSegIndex[i])
+    let end = parseInt(getSegIndex[i + 1])
+    if (i + 1 === getSegIndex.length) {
+      end = data.length
+    }
+    segments.push(data.slice(start, end))
+  }
+  return segments
+}
+
+/**
+ * Get Segment Indexes
+ * @description Helper for {@link split}
+ * @since 1.0.0
+ * @param names
+ * @param data
+ * @param list
+ */
+const getSegIndexes = (names: string[], data: string, list: string[] = []): string[] => {
+  for (let i = 0; i < names.length; i++) {
+    const regex = new RegExp(`(\\n|\\r|)(${names[i]})\\|`, 'g')
+    let m
+    while ((m = regex.exec(data)) != null) {
+      const s = m[0]
+      if (s.includes('\r\n')) {
+        m.index = m.index + 2
+      } else if (s.includes('\n')) {
+        m.index++
+      } else if (s.includes('\r')) {
+        m.index++
+      }
+      if (m.index !== null) {
+        list.push(m.index.toString())
+      }
+    }
+  }
+  return list
+}