Cycle detection when parsing project

build.gradle.kts

@@ -2,7 +2,7 @@ import org.jetbrains.kotlin.konan.properties.Properties
 import java.io.FileInputStream
 
 val artifactIdVal = "dag-command"
-val versionVal = "1.10.0"
+val versionVal = "1.11.0"
 val publicationName = "dagCommand"
 
 group = "io.github.leandroborgesferreira"

src/main/kotlin/io/github/leandroborgesferreira/dagcommand/domain/exception/CycleDetectedException.kt

@@ -0,0 +1,3 @@
+package io.github.leandroborgesferreira.dagcommand.domain.exception
+
+class CycleDetectedException(message: String) : IllegalStateException(message)

src/main/kotlin/io/github/leandroborgesferreira/dagcommand/logic/Graph.kt

@@ -1,6 +1,8 @@
 package io.github.leandroborgesferreira.dagcommand.logic
 
 import io.github.leandroborgesferreira.dagcommand.domain.AdjacencyList
+import io.github.leandroborgesferreira.dagcommand.domain.DagProject
+import io.github.leandroborgesferreira.dagcommand.domain.exception.CycleDetectedException
 import java.util.TreeSet
 
 /**
@@ -42,7 +44,7 @@ private fun traverseGraph(
 ) {
     if (visited.contains(module)) {
         val graphString = "${visited.joinToString(separator = "->")}->$module"
-        throw IllegalStateException(
+        throw CycleDetectedException(
             "A cycle was detected in your graph. The part of the graph with the cycle is: $graphString"
         )
     }
@@ -57,3 +59,47 @@ private fun traverseGraph(
         traverseGraph(adjacencyList, dependentModule, visited + module, resultSet)
     }
 }
+
+internal fun <T> Iterable<T>.iterableToDagProjectT(
+    filterModules: Set<String>,
+    visitedT: Set<String>,
+    getNext: (T) -> Iterable<T>,
+    getName: (T) -> String
+) = map { project -> project.toDagProjectT(filterModules, visitedT, getNext, getName) }
+
+internal fun <T> T.toDagProjectT(
+    filterModules: Set<String>,
+    visitedT: Set<String>,
+    getNext: (T) -> Iterable<T>,
+    getName: (T) -> String,
+): DagProject {
+    val nextDependencies = getNext(this)
+    val nextNames = getNext(this).map(getName)
+    val name = getName(this)
+
+    println(
+        """
+            Current module: $name
+            Next names: ${nextNames.joinToString()}
+        """
+    )
+
+    if (nextNames.any(visitedT::contains)) {
+        val visitedAlready = nextNames.filter(visitedT::contains).distinct().joinToString()
+
+        throw CycleDetectedException(
+            """
+                A cycle was detected in the graph of dependencies of your project.
+                These modules appeared more than once: $visitedAlready. Trying to visit from: $name.
+                All nodes visited already in this path: ${visitedT.joinToString()}
+            """
+        )
+    }
+
+    return DagProject(
+        fullName = name,
+        dependencies = nextDependencies.map { project ->
+            project.toDagProjectT(filterModules, visitedT + name, getNext, getName)
+        }.toSet()
+    )
+}

src/main/kotlin/io/github/leandroborgesferreira/dagcommand/logic/ProjectParse.kt

@@ -5,16 +5,11 @@ import org.gradle.api.Project
 import org.gradle.api.artifacts.ProjectDependency
 
 fun Project.toDagProjectList(filterModules: Set<String>): List<DagProject> =
-    project.subprojects.map { project ->
-        project.toDagProject(filterModules)
-    }
-
-private fun Project.toDagProject(filterModules: Set<String>): DagProject =
-    DagProject(
-        fullName = this.path,
-        dependencies = parseDependencies(filterModules).map { project ->
-            project.toDagProject(filterModules)
-        }.toSet()
+    project.subprojects.iterableToDagProjectT(
+        filterModules = filterModules,
+        visitedT = emptySet(),
+        getNext = { project -> project.parseDependencies(filterModules) },
+        getName = { project -> project.name },
     )
 
 private fun Project.parseDependencies(filterModules: Set<String>): List<Project> {

src/test/kotlin/io/github/leandroborgesferreira/dagcommand/logic/GraphKtTest.kt

@@ -1,8 +1,11 @@
 package io.github.leandroborgesferreira.dagcommand.logic
 
 import io.github.leandroborgesferreira.dagcommand.domain.Node
+import io.github.leandroborgesferreira.dagcommand.domain.exception.CycleDetectedException
+import io.github.leandroborgesferreira.dagcommand.utils.cyclicalObjectGraph
 import io.github.leandroborgesferreira.dagcommand.utils.disconnectedGraph
 import io.github.leandroborgesferreira.dagcommand.utils.graphWithCycle
+import io.github.leandroborgesferreira.dagcommand.utils.objectGraph
 import io.github.leandroborgesferreira.dagcommand.utils.simpleGraph
 import org.junit.Test
 import kotlin.test.assertEquals
@@ -60,8 +63,31 @@ class GraphKtTest {
         assertEquals(expected, result)
     }
 
-    @Test(expected = IllegalStateException::class)
+    @Test(expected = CycleDetectedException::class)
     fun `proves that cycles are detected`() {
         affectedModules(graphWithCycle(), listOf(":A", ":B", ":C"))
     }
+
+    @Test(expected = CycleDetectedException::class)
+    fun `cycles are detected when building DagProject`() {
+        cyclicalObjectGraph()
+            .iterableToDagProjectT(
+                filterModules = emptySet(),
+                visitedT = emptySet(),
+                getNext = { project -> project.next },
+                getName = { project -> project.name },
+            )
+    }
+
+    @Test
+    fun `iterableToDagProjectT should work`() {
+        objectGraph()
+            .iterableToDagProjectT(
+                filterModules = emptySet(),
+                visitedT = emptySet(),
+                getNext = { project -> project.next },
+                getName = { project -> project.name },
+            )
+    }
 }
+

src/test/kotlin/io/github/leandroborgesferreira/dagcommand/utils/GraphGeneration.kt

@@ -86,3 +86,61 @@ fun disconnectedGraph(): Map<String, Set<String>> =
         ":E" to emptySet(),
         ":F" to emptySet()
     )
+
+fun cyclicalObjectGraph(): List<GraphNode> =
+    listOf(
+        GraphNode(
+            name = "A",
+            next = listOf(
+                GraphNode(
+                    name = "B",
+                    next = listOf(
+                        GraphNode(name = "A")
+                    )
+                )
+            )
+        )
+    )
+
+
+fun objectGraph(): List<GraphNode> =
+    listOf(
+        GraphNode(
+            name = "A",
+            next = listOf(
+                GraphNode(
+                    name = "B",
+                    next = listOf(
+                        GraphNode(name = "E")
+                    )
+                )
+            )
+        ),
+        GraphNode(
+            name = "C",
+            next = listOf(
+                GraphNode(
+                    name = "B",
+                    next = listOf(
+                        GraphNode(name = "E")
+                    )
+                )
+            )
+        ),
+        GraphNode(
+            name = "D",
+            next = listOf(
+                GraphNode(
+                    name = "B",
+                    next = listOf(
+                        GraphNode(name = "E")
+                    )
+                )
+            )
+        ),
+    )
+
+data class GraphNode(
+    val name: String,
+    val next: Iterable<GraphNode> = emptySet()
+)