Fix Append Transformation Edge Cases

src/main/java/com/conveyal/datatools/manager/models/transform/AppendToFileTransformation.java

@@ -5,9 +5,11 @@
 import com.conveyal.datatools.manager.models.TableTransformResult;
 import com.conveyal.datatools.manager.models.TransformType;
 
+import java.io.BufferedReader;
 import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.FileOutputStream;
+import java.io.FileReader;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.charset.StandardCharsets;
@@ -49,20 +51,40 @@ public void transform(FeedTransformZipTarget zipTarget, MonitorableJob.Status st
             Path targetTxtFilePath = getTablePathInZip(tableName, targetZipFs);
 
             final File tempFile = File.createTempFile(tableName + "-temp", ".txt");
+            final File tempFileWithStrippedNewlines = File.createTempFile(tableName + "-temp-no-newlines", ".txt");
             Files.copy(targetTxtFilePath, tempFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
 
             // Append CSV data into the target file in the temporary copy of file
             try (OutputStream os = new FileOutputStream(tempFile, true)) {
-                // Append a newline in case our data doesn't include one
-                // Having an extra newline is not a problem!
                 os.write(newLineStream.readAllBytes());
                 os.write(inputStream.readAllBytes());
+                os.flush();
+
             } catch (Exception e) {
                 status.fail("Failed to write to target file", e);
             }
 
+
+            // Re-write file without extra line breaks
+            try (
+                OutputStream noNewlineOs = new FileOutputStream(tempFileWithStrippedNewlines, false);
+                FileReader fr = new FileReader(tempFile);
+                BufferedReader br = new BufferedReader(fr);
+            ) {
+                String line;
+                while ((line = br.readLine()) != null) {
+                    if (line.matches("\n") || line.isEmpty()) {
+                        continue;
+                    }
+
+                    noNewlineOs.write(line.getBytes());
+                    noNewlineOs.write("\n".getBytes());
+                }
+                noNewlineOs.flush();
+            }
+
             // Copy modified file into zip
-            Files.copy(tempFile.toPath(), targetTxtFilePath, StandardCopyOption.REPLACE_EXISTING);
+            Files.copy(tempFileWithStrippedNewlines.toPath(), targetTxtFilePath, StandardCopyOption.REPLACE_EXISTING);
 
             final int NEW_LINE_CHARACTER_CODE = 10;
             int lineCount = (int) csvData.chars().filter(c -> c == NEW_LINE_CHARACTER_CODE).count();

src/test/java/com/conveyal/datatools/manager/jobs/ArbitraryTransformJobTest.java

@@ -216,6 +216,71 @@ void canAppendToStops() throws SQLException, IOException {
                 1
         );
     }
+
+
+    @Test
+    void canAppendToStopsWithLeadingNewlineInData() throws SQLException, IOException {
+        sourceVersion = createFeedVersion(
+                feedSource,
+                zipFolderFiles("fake-agency-with-only-calendar-and-trailing-newlines")
+        );
+        FeedTransformation transformation = AppendToFileTransformation.create(generateStopRowWithLeadingNewline(), "stops");
+        FeedTransformRules transformRules = new FeedTransformRules(transformation);
+        feedSource.transformRules.add(transformRules);
+        Persistence.feedSources.replace(feedSource.id, feedSource);
+        // Create new target version (note: the folder has no stop_attributes.txt file)
+        targetVersion = createFeedVersion(
+                feedSource,
+                zipFolderFiles("fake-agency-with-only-calendar-dates")
+        );
+        LOG.info("Checking assertions.");
+        assertEquals(
+                5 + 3, // Magic number should match row count of stops.txt with three extra
+                targetVersion.feedLoadResult.stops.rowCount,
+                "stops.txt row count should equal input csv data # of rows + 3 extra rows"
+        );
+        // Check for presence of new stop id in database (one record).
+        assertThatSqlCountQueryYieldsExpectedCount(
+                String.format(
+                        "SELECT count(*) FROM %s.stops WHERE stop_id = '%s'",
+                        targetVersion.namespace,
+                        "new"
+                ),
+                1
+        );
+    }
+    @Test
+    void canAppendToStopsWithTrailingNewlineInData() throws SQLException, IOException {
+        sourceVersion = createFeedVersion(
+                feedSource,
+                zipFolderFiles("fake-agency-with-only-calendar-and-trailing-newlines")
+        );
+        FeedTransformation transformation = AppendToFileTransformation.create(generateStopRowWithTrailingNewline(), "stops");
+        FeedTransformRules transformRules = new FeedTransformRules(transformation);
+        feedSource.transformRules.add(transformRules);
+        Persistence.feedSources.replace(feedSource.id, feedSource);
+        // Create new target version (note: the folder has no stop_attributes.txt file)
+        targetVersion = createFeedVersion(
+                feedSource,
+                zipFolderFiles("fake-agency-with-only-calendar-dates")
+        );
+        LOG.info("Checking assertions.");
+        assertEquals(
+                5 + 3, // Magic number should match row count of stops.txt with three extra
+                targetVersion.feedLoadResult.stops.rowCount,
+                "stops.txt row count should equal input csv data # of rows + 3 extra rows"
+        );
+        // Check for presence of new stop id in database (one record).
+        assertThatSqlCountQueryYieldsExpectedCount(
+                String.format(
+                        "SELECT count(*) FROM %s.stops WHERE stop_id = '%s'",
+                        targetVersion.namespace,
+                        "new"
+                ),
+                1
+        );
+    }
+
     @Test
     void canReplaceFeedInfo() throws SQLException, IOException {
         // Generate random UUID for feedId, which gets placed into the csv data.
@@ -311,6 +376,16 @@ private static String generateStopRow() {
                 "\nnew2,new2,appended stop,,37,-122,,,0,123,," +
                 "\nnew,new,appended stop,,37.06668,-122.07781,,,0,123,,";
     }
+    private static String generateStopRowWithLeadingNewline() {
+        return "\nnew3,new3,appended stop,,37,-122,,,0,123,," +
+                "\nnew2,new2,appended stop,,37,-122,,,0,123,," +
+                "\nnew,new,appended stop,,37.06668,-122.07781,,,0,123,,";
+    }
+    private static String generateStopRowWithTrailingNewline() {
+        return "new3,new3,appended stop,,37,-122,,,0,123,," +
+                "\nnew2,new2,appended stop,,37,-122,,,0,123,," +
+                "\nnew,new,appended stop,,37.06668,-122.07781,,,0,123,,\n";
+    }
 
     private static String generateCustomCsvData() {
         return "custom_column1,custom_column2,custom_column3"

src/test/resources/com/conveyal/datatools/gtfs/fake-agency-with-only-calendar-and-trailing-newlines/agency.txt

@@ -0,0 +1,2 @@
+agency_id,agency_name,agency_url,agency_lang,agency_phone,agency_email,agency_timezone,agency_fare_url,agency_branding_url
+1,Fake Transit,,,,,America/Los_Angeles,,

src/test/resources/com/conveyal/datatools/gtfs/fake-agency-with-only-calendar-and-trailing-newlines/calendar.txt

@@ -0,0 +1,3 @@
+service_id,monday,tuesday,wednesday,thursday,friday,saturday,sunday,start_date,end_date
+common_id,1,1,1,1,1,1,1,20170918,20170920
+only_calendar_id,1,1,1,1,1,1,1,20170921,20170922

src/test/resources/com/conveyal/datatools/gtfs/fake-agency-with-only-calendar-and-trailing-newlines/feed_info.txt

@@ -0,0 +1,2 @@
+feed_id,feed_publisher_name,feed_publisher_url,feed_lang,feed_version
+fake_transit,Conveyal,http://www.conveyal.com,en,1.0

src/test/resources/com/conveyal/datatools/gtfs/fake-agency-with-only-calendar-and-trailing-newlines/routes.txt

@@ -0,0 +1,3 @@
+agency_id,route_id,route_short_name,route_long_name,route_desc,route_type,route_url,route_color,route_text_color,route_branding_url
+1,1,1,Route 1,,3,,7CE6E7,FFFFFF,
+1,2,2,Route 2,,3,,7CE6E7,FFFFFF,

src/test/resources/com/conveyal/datatools/gtfs/fake-agency-with-only-calendar-and-trailing-newlines/stop_attributes.txt

@@ -0,0 +1,3 @@
+stop_id,accessibility_id,cardinal_direction,relative_position,stop_city
+4u6g,0,SE,FS,Scotts Valley
+johv,0,SE,FS,Scotts Valley

src/test/resources/com/conveyal/datatools/gtfs/fake-agency-with-only-calendar-and-trailing-newlines/stop_times.txt

@@ -0,0 +1,5 @@
+trip_id,arrival_time,departure_time,stop_id,stop_sequence,stop_headsign,pickup_type,drop_off_type,shape_dist_traveled,timepoint
+only-calendar-trip1,07:00:00,07:00:00,4u6g,1,,0,0,0.0000000,
+only-calendar-trip1,07:01:00,07:01:00,johv,2,,0,0,341.4491961,
+only-calendar-trip2,07:00:00,07:00:00,johv,1,,0,0,0.0000000,
+only-calendar-trip2,07:01:00,07:01:00,4u6g,2,,0,0,341.4491961,

src/test/resources/com/conveyal/datatools/gtfs/fake-agency-with-only-calendar-and-trailing-newlines/stops.txt

@@ -0,0 +1,7 @@
+stop_id,stop_code,stop_name,stop_desc,stop_lat,stop_lon,zone_id,stop_url,location_type,parent_station,stop_timezone,wheelchair_boarding
+4u6g,4u6g,Butler Ln,,37.0612132,-122.0074332,,,0,,,
+johv,johv,Scotts Valley Dr & Victor Sq,,37.0590172,-122.0096058,,,0,,,
+123,,Parent Station,,37.0666,-122.0777,,,1,,,
+
+1234,1234,Child Stop,,37.06662,-122.07772,,,0,123,,
+1234567,1234567,Unused stop,,37.06668,-122.07781,,,0,123,,

src/test/resources/com/conveyal/datatools/gtfs/fake-agency-with-only-calendar-and-trailing-newlines/trips.txt

@@ -0,0 +1,3 @@
+route_id,trip_id,trip_headsign,trip_short_name,direction_id,block_id,shape_id,bikes_allowed,wheelchair_accessible,service_id
+1,only-calendar-trip1,,,0,,,0,0,common_id
+2,only-calendar-trip2,,,0,,,0,0,common_id