Add configuration for setting escaping strategy

Author: josh

Sources/Active/Reader/ReaderConfiguration.swift

@@ -9,6 +9,8 @@ extension CSVReader {
         public var headerStrategy: Strategy.Header
         /// Trims the given characters at the beginning and end of each row, and between fields.
         public var trimStrategry: CharacterSet
+        /// The strategy for escaping quoted fields.
+        public var escapingStrategy: Strategy.Escaping
         /// The encoding used to identify the underlying data or `nil` if you want the CSV reader to try to figure it out.
         ///
         /// If no encoding is provided and the input data doesn't contain a Byte Order Marker (BOM), UTF8 is presumed.
@@ -24,6 +26,7 @@ extension CSVReader {
             self.delimiters = (field: ",", row: "\n")
             self.headerStrategy = .none
             self.trimStrategry = .init()
+            self.escapingStrategy = .doubleQuote
             self.encoding = nil
             self.presample = false
         }
@@ -38,7 +41,7 @@ extension CSVReader {
         /// The characters set to be trimmed at the beginning and ending of each field.
         let trimCharacters: CharacterSet
         /// The unicode scalar used as encapsulator and escaping character (when printed two times).
-        let escapingScalar: Unicode.Scalar? = "\""
+        let escapingScalar: Unicode.Scalar?
 
         /// Creates the inmutable reader settings from the user provided configuration values.
         /// - parameter configuration: The configuration values provided by the API user.
@@ -61,6 +64,8 @@ extension CSVReader {
             }
             // 2. Set the trim characters set.
             self.trimCharacters = configuration.trimStrategry
+            // 3. Set the escaping scalar.
+            self.escapingScalar = configuration.escapingStrategy.scalar
         }
     }
 }

Sources/Strategy.swift

@@ -16,6 +16,32 @@ public enum Strategy {
         }
     }
 
+    /// The strategy for escaping quoted fields.
+    public enum Escaping: ExpressibleByNilLiteral, ExpressibleByUnicodeScalarLiteral {
+        /// CSV delimiters can not be escaped.
+        case none
+        /// Ignore delimiter with in a scalar pair.
+        case scalar(Unicode.Scalar)
+
+        /// Escape double quoted values.
+        public static let doubleQuote: Self = "\""
+
+        public init(nilLiteral: ()) { self = .none }
+        
+        public init(unicodeScalarLiteral value: Unicode.Scalar) {
+            self = .scalar(value)
+        }
+
+        var scalar: Unicode.Scalar? {
+            switch self {
+            case .none:
+                return nil
+            case .scalar(let scalar):
+                return scalar
+            }
+        }
+    }
+
     /// The strategy to use for non-standard floating-point values (IEEE 754 infinity and NaN).
     public enum NonConformingFloat {
         /// Throw upon encountering non-conforming values. This is the default strategy.

Tests/CodableCSVTests/ActiveTests/ReaderTests.swift

@@ -83,6 +83,7 @@ extension ReaderTests {
         let fieldDelimiters: [Delimiter.Field] = [",", ";", "\t", "|", "||", "|-|"]
         let headerStrategy: [Strategy.Header] = [.none, .firstLine, /*.unknown*/]
         let trimStrategy: [CharacterSet] = [.init(), .whitespaces]
+        let escapingStrategy: [Strategy.Escaping] = [.none, .doubleQuote]
         let presamples: [Bool] = [true, false]
         // The data used for testing.
         let (headers, content) = (TestData.headers, TestData.content)
@@ -126,15 +127,18 @@ extension ReaderTests {
                         var toTrim = t
                         if f.rawValue.count == 1, t.contains(f.rawValue.first!) { toTrim.remove(f.rawValue.first!) }
                         if r.rawValue.count == 1, t.contains(r.rawValue.first!) { toTrim.remove(r.rawValue.first!) }
-                        
-                        for p in presamples {
-                            var c = CSVReader.Configuration()
-                            c.delimiters = pair
-                            c.headerStrategy = h
-                            c.trimStrategry = toTrim
-                            c.presample = p
-                            
-                            XCTAssertNoThrow(try work(c, encoded))
+
+                        for e in escapingStrategy {
+                            for p in presamples {
+                                var c = CSVReader.Configuration()
+                                c.delimiters = pair
+                                c.headerStrategy = h
+                                c.trimStrategry = toTrim
+                                c.escapingStrategy = e
+                                c.presample = p
+
+                                XCTAssertNoThrow(try work(c, encoded))
+                            }
                         }
                     }
                 }