Fix serialization of embedded quotes. (#111)

Embedded quotes in values must be doubled, and the entire value surrounded with quotes.
swiftcsv · Aug 30, 2022 · ac327b8 · ac327b8
1 parent 8244fd6
commit ac327b8
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Showing 6 changed files with 60 additions and 10 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -16,6 +16,10 @@ Bugfixes:
 
 - Strip byte order mark from Strings when importing so they don't become part of imported content's cells. 
   See #97 for discussion. (#103) -- @lardieri
+- Respect alternate delimiters when serializing the CSV.
+  See #102 for discussion. (#107) -- @lardieri
+- Escape any double-quotes embedded inside the field values when serializing the CSV.
+  See #111 for discussion. -- @lardieri
 
 Other:
 

diff --git a/SwiftCSV.xcodeproj/project.pbxproj b/SwiftCSV.xcodeproj/project.pbxproj
@@ -86,6 +86,9 @@
 		DFAD8B8028BC8B6F0042BB56 /* Serializer.swift in Sources */ = {isa = PBXBuildFile; fileRef = DFAD8B7A28B601EB0042BB56 /* Serializer.swift */; };
 		DFAD8B8128BC8B700042BB56 /* Serializer.swift in Sources */ = {isa = PBXBuildFile; fileRef = DFAD8B7A28B601EB0042BB56 /* Serializer.swift */; };
 		DFAD8B8228BC8B710042BB56 /* Serializer.swift in Sources */ = {isa = PBXBuildFile; fileRef = DFAD8B7A28B601EB0042BB56 /* Serializer.swift */; };
+		DFAD8B8428BC91D10042BB56 /* wonderland.csv in Resources */ = {isa = PBXBuildFile; fileRef = DFAD8B8328BC91D10042BB56 /* wonderland.csv */; };
+		DFAD8B8528BC91D10042BB56 /* wonderland.csv in Resources */ = {isa = PBXBuildFile; fileRef = DFAD8B8328BC91D10042BB56 /* wonderland.csv */; };
+		DFAD8B8628BC91D10042BB56 /* wonderland.csv in Resources */ = {isa = PBXBuildFile; fileRef = DFAD8B8328BC91D10042BB56 /* wonderland.csv */; };
 		E46085921CCB1E8F00385286 /* large.csv in Resources */ = {isa = PBXBuildFile; fileRef = E46085911CCB1E8F00385286 /* large.csv */; };
 		E46085941CCB1F5C00385286 /* PerformanceTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = E46085931CCB1F5C00385286 /* PerformanceTest.swift */; };
 		F5C19F502283243C00920B06 /* ResourceHelper.swift in Sources */ = {isa = PBXBuildFile; fileRef = F5C19F4F2283243C00920B06 /* ResourceHelper.swift */; };
@@ -158,6 +161,7 @@
 		BE9B02D71CBE57B8009FE424 /* Parser.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Parser.swift; sourceTree = "<group>"; };
 		DF94FE452898F3A3008FD3F9 /* utf8_with_bom.csv */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; path = utf8_with_bom.csv; sourceTree = "<group>"; };
 		DFAD8B7A28B601EB0042BB56 /* Serializer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Serializer.swift; sourceTree = "<group>"; };
+		DFAD8B8328BC91D10042BB56 /* wonderland.csv */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; path = wonderland.csv; sourceTree = "<group>"; };
 		E46085911CCB1E8F00385286 /* large.csv */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; path = large.csv; sourceTree = "<group>"; };
 		E46085931CCB1F5C00385286 /* PerformanceTest.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PerformanceTest.swift; sourceTree = "<group>"; };
 		F5C19F4F2283243C00920B06 /* ResourceHelper.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ResourceHelper.swift; sourceTree = "<group>"; };
@@ -286,10 +290,11 @@
 		BE06B67E1CB72680009578CC /* Res */ = {
 			isa = PBXGroup;
 			children = (
-				DF94FE452898F3A3008FD3F9 /* utf8_with_bom.csv */,
 				BE06B67C1CB7267B009578CC /* empty_fields.csv */,
 				BE06B6811CB7287F009578CC /* quotes.csv */,
 				E46085911CCB1E8F00385286 /* large.csv */,
+				DF94FE452898F3A3008FD3F9 /* utf8_with_bom.csv */,
+				DFAD8B8328BC91D10042BB56 /* wonderland.csv */,
 				F5C19F4F2283243C00920B06 /* ResourceHelper.swift */,
 			);
 			name = Res;
@@ -536,6 +541,7 @@
 			isa = PBXResourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				DFAD8B8428BC91D10042BB56 /* wonderland.csv in Resources */,
 				DF94FE462898F3A3008FD3F9 /* utf8_with_bom.csv in Resources */,
 				BE06B67D1CB7267B009578CC /* empty_fields.csv in Resources */,
 				BE06B6821CB7287F009578CC /* quotes.csv in Resources */,
@@ -554,6 +560,7 @@
 			isa = PBXResourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				DFAD8B8528BC91D10042BB56 /* wonderland.csv in Resources */,
 				DF94FE472898F3A3008FD3F9 /* utf8_with_bom.csv in Resources */,
 				5FB74BEA1CCB9325009DDBF1 /* empty_fields.csv in Resources */,
 				5FB74BEB1CCB9325009DDBF1 /* quotes.csv in Resources */,
@@ -572,6 +579,7 @@
 			isa = PBXResourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				DFAD8B8628BC91D10042BB56 /* wonderland.csv in Resources */,
 				DF94FE482898F3A3008FD3F9 /* utf8_with_bom.csv in Resources */,
 				5FB74BED1CCB932B009DDBF1 /* empty_fields.csv in Resources */,
 				5FB74BEE1CCB932B009DDBF1 /* quotes.csv in Resources */,

diff --git a/SwiftCSV/Serializer.swift b/SwiftCSV/Serializer.swift
@@ -34,13 +34,16 @@ enum Serializer {
 
 fileprivate extension String {
 
+    static let quote = "\""
+
     func enquoted(whenContaining separator: String) -> String {
-        // Add quotes if value contains a delimiter
-        if self.contains(separator) {
-            return "\"\(self)\""
+        // If value contains a delimiter or quotes, double any embedded quotes and surround with quotes.
+        // For more information, see https://www.rfc-editor.org/rfc/rfc4180.html
+        if self.contains(separator) || self.contains(Self.quote) {
+            return Self.quote + self.replacingOccurrences(of: Self.quote, with: Self.quote + Self.quote) + Self.quote
+        } else {
+            return self
         }
-
-        return self
     }
 
 }
diff --git a/SwiftCSVTests/QuotedTests.swift b/SwiftCSVTests/QuotedTests.swift
@@ -33,4 +33,35 @@ class QuotedTests: XCTestCase {
             "age": "8"
         ])
     }
+
+    func testEmbeddedQuotes() throws {
+        let csvURL = ResourceHelper.url(forResource: "wonderland", withExtension: "csv")!
+        csv = try CSV(url: csvURL)
+
+        /*
+         The test file:
+
+         Character,Quote
+         White Rabbit,"""Where shall I begin, please your Majesty?"" he asked."
+         King,"""Begin at the beginning,"" the King said gravely, ""and go on till you come to the end: then stop."""
+         March Hare,"""Do you mean that you think you can find out the answer to it?"" said the March Hare."
+
+         Notice there are no commas (delimiters) in the 3rd line.
+         For more information, see https://www.rfc-editor.org/rfc/rfc4180.html
+         */
+
+        let expected = [
+            [ "Character" : "White Rabbit" , "Quote" : #""Where shall I begin, please your Majesty?" he asked."# ],
+            [ "Character" : "King"         , "Quote" : #""Begin at the beginning," the King said gravely, "and go on till you come to the end: then stop.""# ],
+            [ "Character" : "March Hare"   , "Quote" : #""Do you mean that you think you can find out the answer to it?" said the March Hare."# ]
+        ]
+
+        for (index, row) in csv.rows.enumerated() {
+            XCTAssertEqual(expected[index], row)
+        }
+
+        let serialized = csv.serialized
+        let read = try String(contentsOf: csvURL, encoding: .utf8)
+        XCTAssertEqual(serialized, read)
+    }
 }
diff --git a/SwiftCSVTests/URLTests.swift b/SwiftCSVTests/URLTests.swift
@@ -61,9 +61,9 @@ class URLTests: XCTestCase {
         }
     }
 
-    func testUTF8() {
+    func testUTF8() throws {
         let csvURL = ResourceHelper.url(forResource: "utf8_with_bom", withExtension: "csv")!
-        csv = try! CSV(url: csvURL)
+        csv = try CSV(url: csvURL)
 
         XCTAssertFalse(csv.header.first!.hasPrefix("\u{FEFF}"))
 
@@ -80,9 +80,9 @@ class URLTests: XCTestCase {
         }
     }
 
-    func testUTF8Delimited() {
+    func testUTF8Delimited() throws {
         let csvURL = ResourceHelper.url(forResource: "utf8_with_bom", withExtension: "csv")!
-        csv = try! CSV(url: csvURL, delimiter: .comma)
+        csv = try CSV(url: csvURL, delimiter: .comma)
 
         XCTAssertFalse(csv.header.first!.hasPrefix("\u{FEFF}"))
 

diff --git a/SwiftCSVTests/wonderland.csv b/SwiftCSVTests/wonderland.csv
@@ -0,0 +1,4 @@
+Character,Quote
+White Rabbit,"""Where shall I begin, please your Majesty?"" he asked."
+King,"""Begin at the beginning,"" the King said gravely, ""and go on till you come to the end: then stop."""
+March Hare,"""Do you mean that you think you can find out the answer to it?"" said the March Hare."