From a8af0639b98c02134f94900e285f0568dddac0e4 Mon Sep 17 00:00:00 2001
From: Christian Tietze <christian.tietze@gmail.com>
Date: Thu, 4 Jun 2020 18:24:41 +0200
Subject: [PATCH] fix missing cells at end of enumerated rows

---
 SwiftCSV/EnumeratedView.swift           | 23 ++++++++++++++++++-----
 SwiftCSVTests/CSVTests.swift            |  4 ++--
 SwiftCSVTests/EnumeratedViewTests.swift | 12 ++++++++++++
 3 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/SwiftCSV/EnumeratedView.swift b/SwiftCSV/EnumeratedView.swift
index c17e71f..e71084e 100644
--- a/SwiftCSV/EnumeratedView.swift
+++ b/SwiftCSV/EnumeratedView.swift
@@ -9,7 +9,6 @@
 import Foundation
 
 public struct EnumeratedView: View {
-
     public struct Column {
         public let header: String
         public let rows: [String]
@@ -21,7 +20,6 @@ public struct EnumeratedView: View {
     public private(set) var columns: [Column]
 
     public init(header: [String], text: String, delimiter: Character, loadColumns: Bool = false) throws {
-
         var rows = [[String]]()
         var columns: [EnumeratedView.Column] = []
 
@@ -29,12 +27,14 @@ public struct EnumeratedView: View {
             rows.append(fields)
         }
 
+        // Fill in gaps at the end of rows that are too short.
+        rows = makingRectangular(rows: rows)
+
         if loadColumns {
             columns = header.enumerated().map { (index: Int, header: String) -> EnumeratedView.Column in
-
                 return EnumeratedView.Column(
                     header: header,
-                    rows: rows.map { $0[index] })
+                    rows: rows.map { $0[safe: index] ?? "" })
             }
         }
 
@@ -43,7 +43,6 @@ public struct EnumeratedView: View {
     }
 
     public func serialize(header: [String], delimiter: Character) -> String {
-
         let head = header
             .map(enquoteContentsIfNeeded(cell:))
             .joined(separator: ",") + "\n"
@@ -55,5 +54,19 @@ public struct EnumeratedView: View {
 
         return head + content
     }
+}
 
+extension Collection {
+    subscript (safe index: Self.Index) -> Self.Iterator.Element? {
+        return index < endIndex ? self[index] : nil
+    }
+}
+
+fileprivate func makingRectangular(rows: [[String]]) -> [[String]] {
+    let cellsPerRow = rows.map { $0.count }.max() ?? 0
+    return rows.map { row -> [String] in
+        let missingCellCount = cellsPerRow - row.count 
+        let appendix = Array(repeating: "", count: missingCellCount)
+        return row + appendix
+    }
 }
diff --git a/SwiftCSVTests/CSVTests.swift b/SwiftCSVTests/CSVTests.swift
index 07e3b74..099bf43 100644
--- a/SwiftCSVTests/CSVTests.swift
+++ b/SwiftCSVTests/CSVTests.swift
@@ -31,8 +31,8 @@ class CSVTests: XCTestCase {
         }
     }
     
-    func testInit_whenThereAreIncompleteRows_makesRows() {
-        csv = try! CSV<NamedView>(string: "id,name,age\n1,Alice,18\n2,Bob,19\n3,Charlie")
+    func testInit_whenThereAreIncompleteRows_makesRows() throws {
+        csv = try CSV<NamedView>(string: "id,name,age\n1,Alice,18\n2,Bob,19\n3,Charlie")
         let expected = [
             ["id": "1", "name": "Alice", "age": "18"],
             ["id": "2", "name": "Bob", "age": "19"],
diff --git a/SwiftCSVTests/EnumeratedViewTests.swift b/SwiftCSVTests/EnumeratedViewTests.swift
index 6ef23ca..4a985db 100644
--- a/SwiftCSVTests/EnumeratedViewTests.swift
+++ b/SwiftCSVTests/EnumeratedViewTests.swift
@@ -19,6 +19,18 @@ class EnumeratedViewTests: XCTestCase {
         csv = try! CSV<EnumeratedView>(string: "id,name,age\n1,Alice,18\n2,Bob,19\n3,Charlie,20", delimiter: ",", loadColumns: true)
     }
 
+    func testInit_whenThereAreIncompleteRows_makesRows() throws {
+        csv = try CSV<EnumeratedView>(string: "id,name,age\n1,Alice,18\n2\n3,Charlie", delimiter: ",", loadColumns: true)
+        let expected = [
+            ["1", "Alice", "18"],
+            ["2", "", ""],
+            ["3", "Charlie", ""]
+        ]
+        for (index, row) in csv.rows.enumerated() {
+            XCTAssertEqual(expected[index], row)
+        }
+    }
+
     func testExposesRows() {
         let expected: [[String]] = [
             ["1", "Alice", "18"],