Merge pull request #576 from transitland/onestop_id_name_truncation

Onestop id name truncation

app/services/onestop_id.rb

@@ -87,6 +87,22 @@ class StopOnestopId < OnestopIdBase
   class RouteOnestopId < OnestopIdBase
     PREFIX = :r
     MODEL = Route
+
+    def to_s
+      geohash = @geohash[0...self.class::GEOHASH_MAX_LENGTH]
+      # Both Route and their RouteStopPatterns will share a name component whose max length
+      # is dependent on the fixed length components of the RouteStopPattern onestop id (which includes the Route onestop id)
+      # a variable length route geohash, and the total limitation of 64 chars for all onestop ids.
+      # Route onestop ids will have 1 prefix, 2 dashes, and a variable-length route geohash up to 10 characters long.
+      # RouteStopPattern onestop ids will have a route onestop id plus 2 dashes and 2 geohashes (stop pattern and geometry)
+      # of 6 chars long each. The final max value of the name length is computed in RouteStopPatternOnestopId.max_name_length
+      # and will be between 64 - (1 + 2 + 10 + 2 + 2*6) = 37 and 46 chars long.
+      [
+        self.class::PREFIX,
+        geohash,
+        @name[0...RouteStopPatternOnestopId.max_name_length(geohash.length)],
+      ].join(COMPONENT_SEPARATOR)[0...self.class::MAX_LENGTH]
+    end
   end
 
   class RouteStopPatternOnestopId < OnestopIdBase
@@ -119,10 +135,11 @@ def initialize(string: nil, route_onestop_id: nil, stop_pattern: nil, geometry_c
     end
 
     def to_s
+      geohash = @geohash[0...self.class::GEOHASH_MAX_LENGTH]
       [
         self.class::PREFIX,
-        @geohash[0...self.class::GEOHASH_MAX_LENGTH],
-        @name,
+        geohash,
+        @name[0...self.class.max_name_length(geohash.length)],
         @stop_hash,
         @geometry_hash
       ].join(COMPONENT_SEPARATOR)[0...self.class::MAX_LENGTH]
@@ -145,6 +162,11 @@ def self.route_onestop_id(onestop_id)
       onestop_id.split(COMPONENT_SEPARATOR)[0..2].join(COMPONENT_SEPARATOR)
     end
 
+    def self.max_name_length(geohash_length)
+      num_fixed_chars = NUM_COMPONENTS + 2*(HASH_LENGTH)
+      MAX_LENGTH - (num_fixed_chars + geohash_length)
+    end
+
     private
 
     def validate_hash(value)

spec/services/onestop_id_spec.rb

@@ -70,6 +70,17 @@ class TestOnestopId < OnestopId::OnestopIdBase
     end
   end
 
+  context 'RouteOnestopId' do
+    it 'truncates beyond maximum length' do
+      expect(
+        OnestopId::RouteOnestopId.new(
+          geohash: '9q9',
+          name: 'pneumonoultramicroscopicsilicovolcanoconiosis'
+        ).to_s
+      ).to eq('r-9q9-pneumonoultramicroscopicsilicovolcanoconiosi')
+    end
+  end
+
   context 'RouteStopPatternOnestopId' do
     context 'invalid arguments' do
       it 'fails gracefully when given an invalid stop pattern' do
@@ -116,6 +127,16 @@ class TestOnestopId < OnestopId::OnestopIdBase
       ).to eq('fca1a5')
     end
 
+    it 'truncates beyond maximum length' do
+      expect(
+        OnestopId::RouteStopPatternOnestopId.new(
+          route_onestop_id: 'r-9q9-pneumonoultramicroscopicsilicovolcanoconiosis',
+          stop_pattern: ['s-9q9-stop~1', 's-9q9-stop~2'],
+          geometry_coords: [[-122.0, 40.0], [-121.0, 41.0]]
+        ).to_s
+      ).to eq('r-9q9-pneumonoultramicroscopicsilicovolcanoconiosi-fca1a5-48fed0')
+    end
+
     context '#validate' do
       it 'requires valid route onestop id' do
         expect(