Add dependency graph implementation to backend

rsconcept/backend/apps/rsform/graph.py

@@ -0,0 +1,73 @@
+''' Utility: Graph implementation. '''
+from typing import Dict, Iterable, Optional, cast
+
+
+class Graph:
+    ''' Directed graph. '''
+    def __init__(self, graph: Optional[Dict[str, list[str]]]=None):
+        if graph is None:
+            self._graph = cast(Dict[str, list[str]], dict())
+        else:
+            self._graph = graph
+
+    def contains(self, node_id: str) -> bool:
+        ''' Check if node is in graph. '''
+        return node_id in self._graph
+    
+    def has_edge(self, id_from: str, id_to: str) -> bool:
+        ''' Check if edge is in graph. '''
+        return self.contains(id_from) and id_to in self._graph[id_from]
+
+    def add_node(self, node_id: str):
+        ''' Add node to graph. '''
+        if not self.contains(node_id):
+            self._graph[node_id] = []
+
+    def add_edge(self, id_from: str, id_to: str):
+        ''' Add edge to graph. '''
+        self.add_node(id_from)
+        self.add_node(id_to)
+        if id_to not in self._graph[id_from]:
+            self._graph[id_from].append(id_to)
+
+    def expand_outputs(self, origin: Iterable[str]) -> list[str]:
+        ''' Expand origin nodes forward through graph edges. '''
+        result: list[str] = []
+        marked: set[str] = set(origin)
+        for node_id in origin:
+            if self.contains(node_id):
+                for child_id in self._graph[node_id]:
+                    if child_id not in marked and child_id not in result:
+                        result.append(child_id)
+        position: int = 0
+        while position < len(result):
+            node_id = result[position]
+            position += 1
+            if (node_id not in marked):
+                marked.add(node_id)
+                for child_id in self._graph[node_id]:
+                    if child_id not in marked and child_id not in result:
+                        result.append(child_id)
+        return result
+
+    def topological_order(self) -> list[str]:
+        ''' Return nodes in topological order. '''
+        result: list[str] = []
+        marked: set[str] = set()
+        for node_id in self._graph.keys():
+            if node_id not in marked:
+                to_visit: list[str] = [node_id]
+                while len(to_visit) > 0:
+                    node = to_visit[-1]
+                    if node in marked:
+                        if node not in result:
+                            result.append(node)
+                        to_visit.remove(node)
+                    else:
+                        marked.add(node)
+                        if len(self._graph[node]) > 0:
+                            for child_id in self._graph[node]:
+                                if child_id not in marked:
+                                    to_visit.append(child_id)
+        result.reverse()
+        return result

rsconcept/backend/apps/rsform/tests/__init__.py

@@ -3,3 +3,4 @@ from .t_imports import *
 from .t_views import *
 from .t_models import *
 from .t_serializers import *
+from .t_graph import *

rsconcept/backend/apps/rsform/tests/t_graph.py

@@ -0,0 +1,64 @@
+''' Unit tests: graph. '''
+import unittest
+
+from apps.rsform.graph import Graph
+
+
+class TestGraph(unittest.TestCase):
+    ''' Test class for graph. '''
+    def test_construction(self):
+        ''' Test graph construction methods. '''
+        graph = Graph()
+        self.assertFalse(graph.contains('X1'))
+
+        graph.add_node('X1')
+        self.assertTrue(graph.contains('X1'))
+
+        graph.add_edge('X2', 'X3')
+        self.assertTrue(graph.contains('X2'))
+        self.assertTrue(graph.contains('X3'))
+        self.assertTrue(graph.has_edge('X2', 'X3'))
+        self.assertFalse(graph.has_edge('X3', 'X2'))
+
+        graph = Graph({'X1': ['X3', 'X4'], 'X2': ['X1'], 'X3': [], 'X4': [], 'X5': []})
+        self.assertTrue(graph.contains('X1'))
+        self.assertTrue(graph.contains('X5'))
+        self.assertTrue(graph.has_edge('X1', 'X3'))
+        self.assertTrue(graph.has_edge('X2', 'X1'))
+
+    def test_expand_outputs(self):
+        ''' Test Method: Graph.expand_outputs. '''
+        graph = Graph({
+            'X1': ['X2'],
+            'X2': ['X3', 'X5'],
+            'X3': [],
+            'X5': ['X6'],
+            'X6': ['X1'],
+            'X7': []
+        })
+        self.assertEqual(graph.expand_outputs([]), [])
+        self.assertEqual(graph.expand_outputs(['X3']), [])
+        self.assertEqual(graph.expand_outputs(['X7']), [])
+        self.assertEqual(graph.expand_outputs(['X2', 'X5']), ['X3', 'X6', 'X1'])
+
+    def test_topological_order(self):
+        ''' Test Method: Graph.topological_order. '''
+        self.assertEqual(Graph().topological_order(), [])
+        graph = Graph({
+            'X1': [],
+            'X2': ['X1'],
+            'X3': [],
+            'X4': ['X3'],
+            'X5': ['X6'],
+            'X6': ['X1', 'X2']
+        })
+        self.assertEqual(graph.topological_order(), ['X5', 'X6', 'X4', 'X3', 'X2', 'X1'])
+
+        graph = Graph({
+            'X1': ['X1'],
+            'X2': ['X4'],
+            'X3': ['X2'],
+            'X4': [],
+            'X5': ['X2'],
+        })
+        self.assertEqual(graph.topological_order(), ['X5', 'X3', 'X2', 'X4', 'X1'])

rsconcept/frontend/src/utils/Graph.test.ts

@@ -73,7 +73,7 @@ describe('Testing Graph editing', () => {
 describe('Testing Graph sort', () => {
   test('topological order', () => {
     const graph = new Graph([[9, 1], [9, 2], [2, 1], [4, 3], [5, 9]]);
-    expect(graph.tolopogicalOrder()).toStrictEqual([5, 4, 3, 9, 1, 2]);
+    expect(graph.tolopogicalOrder()).toStrictEqual([5, 4, 3, 9, 2, 1]);
   });
 });
 

rsconcept/frontend/src/utils/Graph.ts

@@ -194,20 +194,19 @@ export class Graph {
   tolopogicalOrder(): number[] {
     const result: number[] = [];
     const marked = new Map<number, boolean>();
+    const toVisit: number[] = [];
     this.nodes.forEach(node => {
       if (marked.get(node.id)) {
         return;
       }
-      const toVisit: number[] = [node.id];
+      toVisit.push(node.id)
-      let index = 0;
       while (toVisit.length > 0) {
-        const item = toVisit[index];
+        const item = toVisit[toVisit.length - 1];
         if (marked.get(item)) {
-          if (!result.find(id => id ===item)) {
+          if (!result.find(id => id === item)) {
             result.push(item);
           } 
-          toVisit.splice(index, 1);
+          toVisit.pop();
-          index -= 1;
         } else {
           marked.set(item, true);
           const itemNode = this.nodes.get(item);
@@ -218,12 +217,8 @@ export class Graph {
               }
             });
           }
-          if (index + 1 < toVisit.length) {
-            index += 1;
-          }
         }
       }
-      marked
     });
     return result.reverse();
   }