Add a multi-language CRAP tool that writes .metrics/crap.edn for uml-viewer.

Score Clojure, Java, Go, TypeScript, Rust, and Python with each language's complexity rules and coverage report.

tests/test_java.py

@@ -0,0 +1,134 @@
+from crapper.languages.java import functions_in_source
+
+SCORE = """
+class Sample {
+    int score(boolean a, boolean b, int[] values) {
+        for (int i = 0; i < values.length; i++) {
+        }
+        for (int value : values) {
+        }
+        while (a) {
+            a = false;
+        }
+        do {
+            b = false;
+        } while (b);
+        if (a && b || values.length > 0) {
+        }
+        try {
+            return a ? 1 : 0;
+        } catch (RuntimeException ex) {
+            return 2;
+        }
+    }
+}
+"""
+
+NESTED = """
+class Sample {
+    int nested(boolean a, boolean b, int[] values) {
+        for (int i = 0; i < values.length; i++) {
+            if (a) {
+            }
+        }
+        for (int value : values) {
+            if (b) {
+            }
+        }
+        while (a) {
+            if (b) {
+            }
+            a = false;
+        }
+        do {
+            if (a) {
+            }
+            b = false;
+        } while (b);
+        try {
+            return a ? (b ? 1 : 0) : 2;
+        } catch (RuntimeException ex) {
+            if (values.length > 0) {
+                return values[0];
+            }
+            return 3;
+        }
+    }
+
+    int switched(int value) {
+        switch (value) {
+            case 1:
+                if (value > 0) {
+                    return 1;
+                }
+                return 0;
+            default:
+                return 2;
+        }
+    }
+}
+"""
+
+ANONYMOUS = """
+class Sample {
+    int outer() {
+        Runnable runnable = new Runnable() {
+            @Override
+            public void run() {
+                if (true) {
+                }
+            }
+        };
+        return 1;
+    }
+}
+"""
+
+
+def test_counts_the_same_decisions_as_crap4java():
+    methods = functions_in_source(SCORE, "Sample.java")
+    assert [(method.name, method.complexity) for method in methods] == [("score", 10)]
+
+    methods = functions_in_source(NESTED, "Sample.java")
+    assert [(method.name, method.complexity) for method in methods] == [
+        ("nested", 13),
+        ("switched", 4),
+    ]
+
+
+def test_anonymous_class_methods_are_not_entries_and_do_not_raise_complexity():
+    methods = functions_in_source(ANONYMOUS, "Sample.java")
+    assert [(method.name, method.complexity) for method in methods] == [("outer", 1)]
+
+
+def test_ignores_constructors_and_names_the_class_for_uml_viewer():
+    source = """
+    package demo.pkg;
+    public class Board {
+        Board() { if (true) {} }
+        public void place(int x) { if (x > 0 && ready) return; }
+        class Inner { void tick() { return; } }
+    }
+    """
+    methods = functions_in_source(source, "src/demo/pkg/Board.java")
+    assert [(method.namespace, method.name, method.complexity) for method in methods] == [
+        ("demo.pkg.Board", "place", 3),
+        ("demo.pkg.Board.Inner", "tick", 1),
+    ]
+    assert methods[0].jacoco_class == "demo.pkg.Board"
+    assert methods[1].jacoco_class == "demo.pkg.Board$Inner"
+
+
+def test_keywords_in_comments_and_strings_are_not_decisions():
+    source = """
+    class Sample {
+        int stable() {
+            String text = "if && || ? case default catch";
+            // if && || ? case default catch
+            /* if && || ? case default catch */
+            return 1;
+        }
+    }
+    """
+    methods = functions_in_source(source, "Sample.java")
+    assert [(method.name, method.complexity) for method in methods] == [("stable", 1)]