fix: depends_on must support conditions (#5)

The depends_on may be a list or a map depending on the
docker-compose spec. It now supports both.

Closes: #4

src/main/kotlin/ch/derlin/dcvizmermaid/data/Service.kt

@@ -1,8 +1,10 @@
 package ch.derlin.dcvizmermaid.data
 
+import ch.derlin.dcvizmermaid.helpers.OrList
+import ch.derlin.dcvizmermaid.helpers.OrMap
 import ch.derlin.dcvizmermaid.helpers.YAML
-import ch.derlin.dcvizmermaid.helpers.YamlUtils.getByPath
 import ch.derlin.dcvizmermaid.helpers.YamlUtils.getListByPath
+import ch.derlin.dcvizmermaid.helpers.YamlUtils.getListOrMapByPath
 
 class Service(val name: String, private val content: YAML) {
 
@@ -13,8 +15,11 @@ class Service(val name: String, private val content: YAML) {
             .map { Link.parse(name, it) }
 
     private fun linksFromDependsOn(): List<Link> =
-        content.getListByPath("depends_on", listOf<String>())
-            .map { Link.parse(name, it) }
+        when (val dependsOn = content.getListOrMapByPath("depends_on")) {
+            is OrList -> dependsOn.list
+            is OrMap -> dependsOn.map.keys
+            else -> listOf()
+        }.map { Link.parse(name, it) }
 
     fun volumes(): List<VolumeBinding> =
         listOf("volumes", "volumes_from")
@@ -27,9 +32,9 @@ class Service(val name: String, private val content: YAML) {
 
     fun envMatchingPorts(): List<MaybeReference> {
         // environments can be expressed either as list, or as map...
-        val environmentValues = when (val env = content.getByPath("environment")) {
-            is Map<*, *> -> env.values.mapNotNull { it as? String }
-            is List<*> -> env.mapNotNull { it as? String }.map { it.substringAfter("=") }
+        val environmentValues = when (val env = content.getListOrMapByPath("environment")) {
+            is OrList -> env.list.map { it.substringAfter("=") }
+            is OrMap -> env.map.values.mapNotNull { it as? String }
             else -> listOf()
         }
         return environmentValues

src/main/kotlin/ch/derlin/dcvizmermaid/helpers/YamlUtils.kt

@@ -5,6 +5,10 @@ import kotlin.reflect.KClass
 
 typealias YAML = Map<String, Any?>
 
+sealed class ListOrMap
+data class OrList(val list: List<String>) : ListOrMap()
+data class OrMap(val map: YAML = mapOf()) : ListOrMap()
+
 @Suppress("UNCHECKED_CAST")
 object YamlUtils {
 
@@ -17,6 +21,12 @@ object YamlUtils {
         value as List<T>
     } ?: default
 
+    fun YAML.getListOrMapByPath(path: String): ListOrMap? = when (val value = this.getByPath(path)) {
+        is List<*> -> OrList(value as List<String>)
+        is Map<*, *> -> OrMap(value as YAML)
+        else -> null
+    }
+
     fun <T : Any> YAML.getByPath(path: String, type: KClass<T>): T? = getByPath(path)?.let {
         require(type.isInstance(it)) { "Wrong type for $it" }
         it as T
@@ -32,5 +42,5 @@ object YamlUtils {
     }
 
     // useful to avoid the "uncheck cast" warnings in the calling code
-    fun Any.asYaml(): YAML = this as YAML
+    fun Any.asYaml(): YAML = (this as? YAML) ?: mapOf()
 }

src/test/kotlin/ch/derlin/dcvizmermaid/data/ServiceTest.kt

@@ -3,6 +3,7 @@ package ch.derlin.dcvizmermaid.data
 import assertk.assertAll
 import assertk.assertThat
 import assertk.assertions.isEqualTo
+import ch.derlin.dcvizmermaid.helpers.YamlUtils
 import org.junit.jupiter.api.Test
 
 class ServiceTest {
@@ -20,6 +21,36 @@ class ServiceTest {
         }
     }
 
+    @Test
+    fun `parse depends_on as list or map form`() {
+
+        assertAll {
+            listOf(
+                """
+                depends_on:
+                - foo
+                - bar
+                """,
+                """
+                depends_on:
+                  foo:
+                  bar:
+                """,
+                """
+                depends_on:
+                  foo:
+                    condition: service_healthy
+                  bar:
+                    condition: service_completed_successfully
+                """
+            ).forEach { yaml ->
+                assertThat(yaml)
+                    .transform { Service("service", YamlUtils.load(yaml)).links().map { it.to } }
+                    .isEqualTo(listOf("foo", "bar"))
+            }
+        }
+    }
+
     @Test
     fun `parse maybe reference`() {
         val dockerHostIp = "$" + "{" + "DOCKER_HOST_IP" + "}"