fix(parse): Handle escaped escape properly #340

.run/Run Examples.run.xml

@@ -0,0 +1,12 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="Run Examples" type="js.build_tools.npm">
+    <package-json value="$PROJECT_DIR$/package.json" />
+    <command value="run" />
+    <scripts>
+      <script value="examples" />
+    </scripts>
+    <node-interpreter value="project" />
+    <envs />
+    <method v="2" />
+  </configuration>
+</component>

.run/Serve Docs.run.xml

@@ -0,0 +1,12 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="Serve Docs" type="js.build_tools.npm">
+    <package-json value="$PROJECT_DIR$/documentation/package.json" />
+    <command value="run" />
+    <scripts>
+      <script value="start" />
+    </scripts>
+    <node-interpreter value="project" />
+    <envs />
+    <method v="2" />
+  </configuration>
+</component>

.run/jest.config.js.run.xml

@@ -0,0 +1,13 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="Run Tests" type="JavaScriptTestRunnerJest">
+    <config-file value="$PROJECT_DIR$/jest.config.js" />
+    <node-interpreter value="project" />
+    <node-options value="" />
+    <jest-package value="$PROJECT_DIR$/node_modules/jest" />
+    <working-dir value="$PROJECT_DIR$/packages/parse" />
+    <jest-options value="--runInBand --coverage" />
+    <envs />
+    <scope-kind value="ALL" />
+    <method v="2" />
+  </configuration>
+</component>

packages/parse/__tests__/issues/issue340.spec.ts

@@ -0,0 +1,22 @@
+import { EOL } from 'os';
+import { parseString, RowMap, RowArray } from '../../src';
+
+describe('Issue #340 - https://github.com/C2FO/fast-csv/issues/340', () => {
+    const CSV_CONTENT = ['Col1', `"A '"Good'" row''"`, 'Row 2'].join(EOL);
+    const expectedRows = [{ Col1: `A "Good" row'` }, { Col1: 'Row 2' }];
+
+    it('handle a trailing escape', (done) => {
+        const invalid: RowArray[] = [];
+        const rows: RowMap[] = [];
+        parseString(CSV_CONTENT, { headers: true, escape: "'" })
+            .on('data-invalid', (row: RowArray) => invalid.push(row))
+            .on('data', (r: RowMap) => rows.push(r))
+            .on('error', done)
+            .on('end', (count: number) => {
+                expect(rows).toEqual(expectedRows);
+                expect(invalid).toHaveLength(0);
+                expect(count).toBe(expectedRows.length + invalid.length);
+                done();
+            });
+    });
+});

packages/parse/__tests__/parser/column/QuotedColumnParser.spec.ts

@@ -481,6 +481,13 @@ describe('QuotedColumnParser', () => {
                 expect(scanner.lineFromCursor).toBe(',"world"');
             });
 
+            it('should parse an escape followed by another escape', () => {
+                const line = '"hello$$","world"';
+                const { scanner, col } = parse(line, true, { escape: '$' });
+                expect(col).toBe('hello$');
+                expect(scanner.lineFromCursor).toBe(',"world"');
+            });
+
             it('should parse a quoted col up to a LF', () => {
                 const line = '"hello"\n"world"';
                 const { scanner, col } = parse(line, true, { escape: '$' });

packages/parse/src/parser/column/QuotedColumnParser.ts

@@ -35,7 +35,7 @@ export class QuotedColumnParser {
                 throw new Error(
                     `Parse Error: missing closing: '${
                         this.parserOptions.quote
-                    }' in line: at '${scanner.lineFromCursor.replace(/[r\n]/g, "\\n'")}'`,
+                    }' in line: at '${scanner.lineFromCursor.replace(/[\r\n]/g, "\\n'")}'`,
                 );
             }
             return null;
@@ -62,7 +62,11 @@ export class QuotedColumnParser {
                     const tokenFollowingEscape = scanner.nextCharacterToken;
                     // if the character following the escape is a quote character then just add
                     // the quote and advance to that character
-                    if (tokenFollowingEscape !== null && isTokenQuote(tokenFollowingEscape, parserOptions)) {
+                    if (
+                        tokenFollowingEscape !== null &&
+                        (isTokenQuote(tokenFollowingEscape, parserOptions) ||
+                            isTokenEscapeCharacter(tokenFollowingEscape, parserOptions))
+                    ) {
                         characters.push(tokenFollowingEscape.token);
                         nextToken = tokenFollowingEscape;
                     } else if (isQuote) {