[New Check] SimilarTagValueCheck (osmlab#500)

* SimilarTagCheck

* Create instructions

Create instructions.
Added Similar class.
Replaced filter similars function chain to its own function to help clean up flag function body.

* Duplicates fix suggestion

* Documentation

* Tests

* Spotless

* Live examples

* Single character variable names

* Fix suggestion doc

* Configurables description

* More tests

* More configurables

* Code smell

* SpotlessApply

* Function ordering

* HTML characters in javadoc

* Configurables in docs

config/configuration.json

@@ -959,6 +959,35 @@
       "tags":"highway"
     }
   },
+  "SimilarTagValueCheck": {
+    "filter": {
+      "commonSimilars": [
+        ["american", "mexican"], ["cafe", "cake"], ["male", "female"], ["woman", "man"],
+        ["women", "men"], ["male_toilet", "female_toilet"], ["radiology", "cardiology"],
+        ["baseball", "basketball"], ["bowls", "boules"], ["padel", "paddel"], ["formal", "informal"],
+        ["hotel", "hostel"], ["hump", "bump"], ["seed", "feed"]
+      ],
+      "tags": [
+        "asset_ref", "collection_times", "except", "is_in", "junction:ref", "maxspeed:conditional",
+        "old_name", "old_ref", "opening_hours", "ref", "restriction_hours", "route_ref", "supervised",
+        "source_ref", "target", "telescope"
+      ],
+      "tagsWithSubCategories": [
+        "addr", "alt_name", "destination", "name", "seamark", "turn"
+      ]
+    },
+    "similarity.threshold": {
+      "min": 0.0,
+      "max": 1.0
+    },
+    "value.length.min": 4.0,
+    "challenge": {
+      "description": "Tasks identify duplicate/similar values in tags.",
+      "blurb": "Duplicate/Similar tag values.",
+      "instruction": "Determine if the duplicate/similar value is necessary or can be removed.",
+      "difficulty": "EASY"
+    }
+  },
   "SingleSegmentMotorwayCheck": {
     "challenge": {
       "description": "Tasks that identify ways tagged with highway=motorway that are not connected to any ways tagged the same.",

docs/available_checks.md

@@ -86,6 +86,7 @@ This document is a list of tables with a description and link to documentation f
 | [MixedCaseNameCheck](checks/mixedCaseNameCheck.md) | The purpose of this check is to identify names that contain invalid mixed cases so that they can be edited to be the standard format. |
 | [RoadNameGapCheck](checks/RoadNameGapCheck.md) | The purpose of this check is to identify edge connected between two edges whose name tag is same. Flag the edge if the edge has a name tag different to name tag of edges connected to it or if there is no name tag itself.
 | [RoadNameSpellingConsistencyCheck](checks/RoadNameSpellingConsistencyCheck.md) | The purpose of this check is to identify road segments that have a name Tag with a different spelling from that of other segments of the same road. This check is primarily meant to catch small errors in spelling, such as a missing letter, letter accent mixups, or capitalization errors. |
+| [SimilarTagValueCheck](checks/SimilarTagValueCheck.md) | The purpose of this check is to identify tags whose values are either duplicates or similar enough to warrant someone to look at them. |
 | ShortNameCheck | The short name check will validate that any and all names contain at least 2 letters in the name. |
 | [StreetNameIntegersOnlyCheck](checks/streetNameIntegersOnlyCheck.md) | The purpose of this check is to identify streets whose names contain integers only. |
 | [TollValidationCheck](checks/tollValidationCheck) | The purpose of this check is to identify ways that need to have their toll tags investigated/added/removed.

docs/checks/similarTagValueCheck.md

@@ -0,0 +1,52 @@
+# SimilarTagValueCheck
+
+#### Description
+
+The purpose of this check is to identify tags whose values are either duplicates or similar
+enough to warrant someone to look at them.
+
+Configurables: 
+* "value.length.min": Minimum length an individual value must be to be considered for inspection, value.length >= min. 
+* "similarity.threshold.min": Minimum edit distance between two values to be added to the flag where a value of 0 is 
+   used to include duplicates, value >= min.
+* "similarity.threshold.max": Maximum edit distance between two values to be added to the flag, value <= max.
+* "filter.commonSimilars": values that can commonly be found together validly on a tag that are similar but with no 
+   action needed to be taken.
+* "filter.tags": tags that commonly have values that are duplicates/similars that are valid.
+* "filter.tagsWithSubCategories": tags that contain one or many sub-categories that commonly have valid 
+   duplicate/similar values.
+
+#### Live Examples
+Similar tag values
+1. The node [5142510561](https://www.openstreetmap.org/way/5142510561) has the similar values: "crayfish" and "Crayfish"
+
+Duplicate tag values
+1. The way [173171120](https://www.openstreetmap.org/way/173171120) has multiple duplicate values in the "source" tag
+
+#### Code Review
+
+This check evaluates all atlas objects that can hold OSM tags.
+Any duplicate tags are removed in a feature change, while similars are flagged for user review.
+
+#### Validating the object
+The incoming object must:
+* have at least one tag with multiple values (contains a ";")
+
+#### Flagging the object
+We filter out all tags that:
+* are tags that commonly contain valid duplicate/similar values
+* values that are similar to others that commonly occur on the same tag
+* values that either contain: length shorter than the defined min length, a number, non-latin characters
+* the last filtering step we remove any tags that do not contain multiple values
+
+We then take the valid tags and compare each value computing similarity between each, using the
+Levenshtein Edit Distance algorithm. We keep value pairs with a similarity that falls within our 
+similarity threshold.
+
+From there we split the gathered pairs between those that are duplicate values, and those that are similar.
+The duplicates are added to the instructions and used to create a fix suggestion.
+The similars are just added to the instructions.
+
+#### Fix Suggestion
+We create fix suggestions only on duplicate values, as similar values are difficult to determine which one (if not both)
+should be kept. The fix, for duplicates, is to remove all but one occurrence of the duplicate value from the tag.