feat: 🎸 added getNodeDeepness to TreeState

Author: diogofcunha

index.d.ts

@@ -146,6 +146,7 @@ export interface TreeState {
   getTree: (state: State) => Node[];
   createFromTree: (tree: Node[]) => State;
   getNumberOfVisibleDescendants: (state: State, index: number) => number;
+  getNodeDeepness: (state: State, index: number) => number;
 }
 
 export interface TreeStateModifiers {

src/state/TreeState.js

@@ -41,6 +41,26 @@ export default class TreeState {
     return getNodeFromPath(rowPath, state.tree);
   };
 
+  /**
+   * Given a state, finds a node deepness at a certain row index.
+   * @param {State} state - The current state
+   * @param {number} index - The visible row index
+   * @return {number} The node deepness
+   */
+  static getNodeDeepness = (state, index) => {
+    validateState(state);
+
+    const rowPath = state.flattenedTree[index];
+
+    if (!rowPath) {
+      throw Error(
+        `Tried to get node at row "${index}" but got nothing, the tree are ${state.flattenedTree.length} visible rows`,
+      );
+    }
+
+    return rowPath.length - 1;
+  };
+
   /**
    * Given a state and an index, finds the number of visible descendants
    * @param {State} state - The current state

src/state/__tests__/TreeState.test.js

@@ -62,6 +62,29 @@ describe('TreeState', () => {
     });
   });
 
+  describe('getNodeDeepness', () => {
+    test('should get the correct deepness for existing rowId', () => {
+      expect(TreeState.getNodeDeepness(TreeState.createFromTree(Nodes), 0)).toBe(0);
+      expect(TreeState.getNodeDeepness(TreeState.createFromTree(Nodes), 1)).toBe(1);
+      expect(TreeState.getNodeDeepness(TreeState.createFromTree(Nodes), 2)).toBe(2);
+      expect(TreeState.getNodeDeepness(TreeState.createFromTree(Nodes), 3)).toBe(2);
+      expect(TreeState.getNodeDeepness(TreeState.createFromTree(Nodes), 6)).toBe(0);
+    });
+
+    test('should fail with a custom error when supplied rowId does not exist', () => {
+      expect(() => TreeState.getNodeDeepness(TreeState.createFromTree(Nodes), 40)).toThrowErrorMatchingSnapshot();
+    });
+
+    test('should fail for when invalid state is supplied', () => {
+      expect(() => TreeState.getNodeDeepness('state', 0)).toThrowError('Expected a State instance but got string');
+      expect(() => TreeState.getNodeDeepness(1225, 0)).toThrowError('Expected a State instance but got number');
+      expect(() => TreeState.getNodeDeepness([], 0)).toThrowError('Expected a State instance but got object');
+      expect(() => TreeState.getNodeDeepness({}, 0)).toThrowError('Expected a State instance but got object');
+      expect(() => TreeState.getNodeDeepness(true, 0)).toThrowError('Expected a State instance but got boolean');
+      expect(() => TreeState.getNodeDeepness(() => {}, 0)).toThrowError('Expected a State instance but got function');
+    });
+  });
+
   describe('getNumberOfVisibleDescendants', () => {
     test('should fail for when invalid state is supplied', () => {
       expect(() => TreeState.getNumberOfVisibleDescendants('state', 0)).toThrowError(

src/state/__tests__/__snapshots__/TreeState.test.js.snap

@@ -96,3 +96,5 @@ Object {
   },
 }
 `;
+
+exports[`TreeState getNodeDeepness should fail with a custom error when supplied rowId does not exist 1`] = `"Tried to get node at row \\"40\\" but got nothing, the tree are 7 visible rows"`;