fix: read CSV file from a path relative to the model directory (#81)

src/CodeGen.js

@@ -19,7 +19,7 @@ export let codeGenerator = (parseTree, opts) => {
     outputAllVars = true
   }
   // Function to generate a section of the code
-  let generateSection = R.map(v => new EquationGen(v, extData, directData, mode).generate())
+  let generateSection = R.map(v => new EquationGen(v, extData, directData, mode, modelDirname).generate())
   let section = R.pipe(generateSection, R.flatten, lines)
   function generate() {
     // Read variables and subscript ranges from the model parse tree.

src/EquationGen.js

@@ -1,3 +1,4 @@
+import path from 'path'
 import R from 'ramda'
 import XLSX from 'xlsx'
 import { ModelLexer, ModelParser } from 'antlr4-vensim'
@@ -34,7 +35,7 @@ import {
 } from './Helpers.js'
 
 export default class EquationGen extends ModelReader {
-  constructor(variable, extData, directData, mode) {
+  constructor(variable, extData, directData, mode, modelDirname) {
     super()
     // the variable we are generating code for
     this.var = variable
@@ -44,6 +45,8 @@ export default class EquationGen extends ModelReader {
     this.directData = directData
     // set to 'decl', 'init-lookups', 'eval', etc depending on the section being generated
     this.mode = mode
+    // The model directory is required when reading data files for GET DIRECT DATA.
+    this.modelDirname = modelDirname
     // Maps of LHS subscript families to loop index vars for lookup on the RHS
     this.loopIndexVars = new LoopIndexVars(['i', 'j', 'k'])
     this.arrayIndexVars = new LoopIndexVars(['v', 'w'])
@@ -351,7 +354,8 @@ export default class EquationGen extends ModelReader {
         }
       } else {
         // The file is a CSV pathname. Read it now.
-        let data = readCsv(file, tab)
+        let csvPathname = path.resolve(this.modelDirname, file)
+        let data = readCsv(csvPathname, tab)
         if (data) {
           getCellValue = (c, r) => (data[r] != null ? cdbl(data[r][c]) : null)
         }