fix(build): migrate filesystem access to smartfs and tighten TypeScript compatibility

ts/smarthbs.variables.ts

@@ -27,7 +27,8 @@ export let findVarsInHbsString = async (hbsStringArg: string) => {
 
   // make sure we are clean from curly brackets
   varNameArray = varNameArray.map((x) => {
-    return x.match(nameInCurlsRegex)[0];
+    const match = x.match(nameInCurlsRegex);
+    return match ? match[0] : '';
   });
 
   // make sure are uniq
@@ -44,7 +45,7 @@ export let findVarsInHbsString = async (hbsStringArg: string) => {
  * @param varObjectArg
  * @return string array with missing variable names
  */
-export let checkVarsSatisfaction = async (hbsStringArg: string, varObjectArg: any) => {
+export let checkVarsSatisfaction = async (hbsStringArg: string, varObjectArg: Record<string, unknown>) => {
   // required vars as combined deep string with . notation
   let requiredVarStrings = await findVarsInHbsString(hbsStringArg);
 
@@ -55,14 +56,17 @@ export let checkVarsSatisfaction = async (hbsStringArg: string, varObjectArg: an
   // building the
   for (let stringVar of requiredVarStrings) {
     let splittedVars = stringVar.split('.');
-    let requiredPointer = suppliedVarsObject;
+    let requiredPointer: unknown = suppliedVarsObject;
     for (let i = 0; i < splittedVars.length; i++) {
       let splitVar = splittedVars[i];
-      let varAvailable = requiredPointer[splitVar] !== undefined;
+      const pointerObject = requiredPointer && typeof requiredPointer === 'object'
+        ? requiredPointer as Record<string, unknown>
+        : {};
+      let varAvailable = pointerObject[splitVar] !== undefined;
       if (varAvailable && splittedVars.length === i + 1) {
         // ok
       } else if (varAvailable) {
-        requiredPointer = requiredPointer[splitVar];
+        requiredPointer = pointerObject[splitVar];
       } else {
         missingVarsObject.push(stringVar);
         i = splittedVars.length;