From 2ec2db21e3c39bb21a0b52b84f42738e4b0b0fc1 Mon Sep 17 00:00:00 2001
From: Tomasz Fijalkowski <3066563+tfij@users.noreply.github.com>
Date: Tue, 2 Jan 2024 21:12:41 +0100
Subject: [PATCH] support optional `component` keyword in PlantUML diagram
 rules

It is valid PlantUML syntax to prepend the `component` keyword to a component
declaration, e.g.

```
component [MyComponent] <<..mycmp..>>
```

Since it doesn't create a big overhead to support this as an optional part
of the component declaration, we can add it to make it easier for users
that distinguish their components from other types of objects like databases.

Signed-off-by: Tomasz Fijalkowski <3066563+tfij@users.noreply.github.com>
---
 .../plantuml/rules/PlantUmlPatterns.java        |  9 ++++++++-
 .../plantuml/rules/PlantUmlParserTest.java      | 17 +++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/archunit/src/main/java/com/tngtech/archunit/library/plantuml/rules/PlantUmlPatterns.java b/archunit/src/main/java/com/tngtech/archunit/library/plantuml/rules/PlantUmlPatterns.java
index b1a741b05..a7ce0cfbc 100644
--- a/archunit/src/main/java/com/tngtech/archunit/library/plantuml/rules/PlantUmlPatterns.java
+++ b/archunit/src/main/java/com/tngtech/archunit/library/plantuml/rules/PlantUmlPatterns.java
@@ -34,6 +34,7 @@
 import static java.util.Collections.singletonList;
 
 class PlantUmlPatterns {
+    private static final String OPTIONAL_COMPONENT_KEYWORD_FORMAT = "(?:component)?";
     private static final String COMPONENT_NAME_GROUP_NAME = "componentName";
     private static final String COMPONENT_NAME_FORMAT = "\\[" + capture(anythingBut("\\[\\]"), COMPONENT_NAME_GROUP_NAME) + "]";
 
@@ -46,7 +47,13 @@ class PlantUmlPatterns {
     private static final String COLOR_FORMAT = "\\s*(?:#" + anyOf("\\w|/\\\\-") + "+)?";
 
     private static final Pattern PLANTUML_COMPONENT_PATTERN = Pattern.compile(
-            "^\\s*" + COMPONENT_NAME_FORMAT + "\\s*" + STEREOTYPE_FORMAT + "*" + ALIAS_FORMAT + COLOR_FORMAT + "\\s*");
+            "^\\s*" + OPTIONAL_COMPONENT_KEYWORD_FORMAT
+                    + "\\s*" + COMPONENT_NAME_FORMAT
+                    + "\\s*" + STEREOTYPE_FORMAT + "*"
+                    + ALIAS_FORMAT
+                    + COLOR_FORMAT
+                    + "\\s*"
+    );
 
     private static String capture(String pattern) {
         return "(" + pattern + ")";
diff --git a/archunit/src/test/java/com/tngtech/archunit/library/plantuml/rules/PlantUmlParserTest.java b/archunit/src/test/java/com/tngtech/archunit/library/plantuml/rules/PlantUmlParserTest.java
index 4ddcf9814..873d8dde4 100644
--- a/archunit/src/test/java/com/tngtech/archunit/library/plantuml/rules/PlantUmlParserTest.java
+++ b/archunit/src/test/java/com/tngtech/archunit/library/plantuml/rules/PlantUmlParserTest.java
@@ -437,6 +437,23 @@ public void ignores_database_components() {
         assertThat(b.getDependencies()).isEmpty();
     }
 
+    @Test
+    public void supports_components_declared_with_component_keyword() {
+        File file = TestDiagram.in(temporaryFolder)
+                .rawLine("component [CompA] <<..c1..>>")
+                .rawLine("component [Comp B] <<..c2..>> as CompB")
+                .dependencyFrom("CompA").to("CompB")
+                .write();
+
+        PlantUmlDiagram diagram = createDiagram(file);
+
+        PlantUmlComponent a = getComponentWithName("CompA", diagram);
+        PlantUmlComponent b = getComponentWithAlias(new Alias("CompB"), diagram);
+
+        assertThat(a.getDependencies()).containsOnly(b);
+        assertThat(b.getDependencies()).isEmpty();
+    }
+
     private PlantUmlComponent getComponentWithName(String componentName, PlantUmlDiagram diagram) {
         PlantUmlComponent component = diagram.getAllComponents().stream()
                 .filter(c -> c.getComponentName().asString().equals(componentName))