Answer

.gitignore

@@ -1 +1,2 @@
 node_modules
+desktop.ini

index.js

@@ -0,0 +1,60 @@
+function validateLineup(inputLineup){
+// if the lineup is too long, no need to do any calculations
+if (inputLineup.length > 9) return false
+
+
+ // calculate our total salary, if it's more than %45,000 return false and exit function
+ const totalSalary = inputLineup.reduce((previous, array) => previous + array.salary, 0)
+ if (totalSalary >= 45000) return false
+
+ // Make sure too many teammates aren't on the same team, if so, return false
+ if(countUniqueProperties(inputLineup, 'teamId', 2)) return false
+ // Same function can be used for same game away well
+  if (countUniqueProperties(inputLineup, 'gameId', 3)) return false
+
+  // Now check our positions, this is in a new function due to how big it is
+if(!invalidPositions(inputLineup)) return false
+
+// if nothing has been returned yet..then return true as all conditions must have been true
+return true
+
+
+}
+
+function countUniqueProperties(array, propertyName, numberAllowed){
+    // make an array to hold our results
+    let resultArray = []
+
+    // make an array of every result we are looking for
+    const allResults = array.map(array => array[propertyName])
+    // now trim all results and get each unique value
+    const uniqueResults = [...new Set(allResults)]
+
+    // now count each unique results entries, and add it as an object in our array
+    uniqueResults.forEach(element => {
+        resultArray.push(allResults.filter(name => name === element).length )
+
+    });
+
+    // now check our array to see if there are more then allowed
+    return Math.max(...resultArray) > numberAllowed
+}
+
+function invalidPositions(array){
+    // make an array of every result we are looking for
+    let players = array.map(array => array.position)
+
+    // now check if there is 3 OF, and remove from array
+    let outFieldArray = players.filter(player => player === 'OF')
+    let otherArray = players.filter(player => player != 'OF')
+
+    // now we check if our OF count is correct and our players are all unique positions and there are 6 of them
+    // if all 3 is true then we have 3 OF and a P, C, 1B, 2B, 3B, and SS
+    return JSON.stringify(otherArray) === JSON.stringify([...new Set(otherArray)]) && outFieldArray.length === 3 &&
+    otherArray.length === 6
+
+
+}
+
+
+module.exports = validateLineup