Query interface segregation candidates for Typescript

Author: JohT

cypher/Internal_Dependencies/Candidates_for_Interface_Segregation_for_Typescript.cypher

@@ -0,0 +1,27 @@
+// Candidates for Interface Segregation for Typescript
+
+MATCH (type:Type)-[:DECLARES]->(method:Method)-[:INVOKES]->(dependentMethod:Method)
+MATCH (dependentMethod)<-[:DECLARES]-(dependentType:Type)
+MATCH (dependentType)-[:IMPLEMENTS*1..9]->(superType:Type)-[:DECLARES]->(inheritedMethod:Method)
+WHERE type.fqn <> dependentType.fqn
+  AND dependentMethod.name IS NOT NULL
+  AND inheritedMethod.name IS NOT NULL
+  AND dependentMethod.name <> '<init>' // ignore constructors
+  AND inheritedMethod.name <> '<init>' // ignore constructors
+ WITH type.fqn                               AS fullTypeName
+     ,dependentType.fqn                      AS fullDependentTypeName
+     ,collect(DISTINCT dependentMethod.name) AS calledMethodNames
+     ,count(DISTINCT dependentMethod)        AS calledMethods
+     // Count the different signatures without the return type
+     // of all declared methods including the inherited ones
+     ,count(DISTINCT split(method.signature, ' ')[1]) + count(DISTINCT split(inheritedMethod.signature, ' ')[1]) AS declaredMethods
+// Filter out types that declare only a few more methods than those that are actually used.
+// A good interface segregation candidate declares a lot of methods where only a few of them are used widely.
+WHERE declaredMethods > calledMethods + 2
+ WITH fullDependentTypeName
+     ,declaredMethods
+     ,calledMethodNames
+     ,calledMethods
+     ,count(DISTINCT fullTypeName) AS callerTypes
+ RETURN fullDependentTypeName, declaredMethods, calledMethodNames, calledMethods, callerTypes
+ ORDER BY callerTypes DESC, declaredMethods DESC, fullDependentTypeName

jupyter/InternalDependenciesTypescript.ipynb

@@ -381,7 +381,7 @@
    "source": [
     "### Table 4 - Top 40 most used combinations of methods\n",
     "\n",
-    "The following table shows the top 40 most used combinations of methods of larger types that might benefit from applying the *Interface Segregation Principle*. The whole table can be found in the CSV report `Candidates_for_Interface_Segregation`."
+    "The following table shows the top 40 most used combinations of methods of larger types that might benefit from applying the *Interface Segregation Principle*. The whole table can be found in the CSV report `Candidates_for_Interface_Segregation_for_Typescript`."
    ]
   },
   {
@@ -393,7 +393,7 @@
    },
    "outputs": [],
    "source": [
-    "interface_segregation_candidates=query_cypher_to_data_frame(\"../cypher/Candidates_for_Interface_Segregation.cypher\", limit=40)\n",
+    "interface_segregation_candidates=query_cypher_to_data_frame(\"../cypher/Internal_Dependencies/Candidates_for_Interface_Segregation_for_Typescript.cypher\", limit=40)\n",
     "interface_segregation_candidates"
    ]
   },

scripts/reports/InternalDependenciesCsv.sh

@@ -49,6 +49,7 @@ execute_cypher "${CYCLIC_DEPENDENCIES_CYPHER_DIR}/Cyclic_Dependencies_between_Ar
 execute_cypher "${CYCLIC_DEPENDENCIES_CYPHER_DIR}/Cyclic_Dependencies_for_Typescript.cypher" > "${FULL_REPORT_DIRECTORY}/Cyclic_Dependencies_for_Typescript.csv"
 
 execute_cypher "${INTERNAL_DEPENDENCIES_CYPHER_DIR}/Candidates_for_Interface_Segregation.cypher" > "${FULL_REPORT_DIRECTORY}/InterfaceSegregationCandidates.csv"
+execute_cypher "${INTERNAL_DEPENDENCIES_CYPHER_DIR}/Candidates_for_Interface_Segregation_for_Typescript.cypher" > "${FULL_REPORT_DIRECTORY}/Candidates_for_Interface_Segregation_for_Typescript.csv"
 
 execute_cypher "${INTERNAL_DEPENDENCIES_CYPHER_DIR}/List_all_Java_artifacts.cypher" > "${FULL_REPORT_DIRECTORY}/List_all_Java_artifacts.csv"
 execute_cypher "${INTERNAL_DEPENDENCIES_CYPHER_DIR}/List_types_that_are_used_by_many_different_packages.cypher" > "${FULL_REPORT_DIRECTORY}/WidelyUsedTypes.csv"