Fix: data links error

src/components/graph/graph.helper.js

@@ -30,7 +30,7 @@ import CONST from "./graph.const";
 import DEFAULT_CONFIG from "./graph.config";
 import ERRORS from "../../err";
 
-import { isDeepEqual, isEmptyObject, merge, pick, antiPick, throwErr } from "../../utils";
+import { isDeepEqual, isEmptyObject, merge, pick, antiPick, throwErr, throwWarning } from "../../utils";
 import { computeNodeDegree } from "./collapse.helper";
 
 const NODE_PROPS_WHITELIST = ["id", "highlighted", "x", "y", "index", "vy", "vx"];
@@ -205,9 +205,10 @@ function _tagOrphanNodes(nodes, linksMatrix) {
  * Some integrity validations on links and nodes structure. If some validation fails the function will
  * throw an error.
  * @param  {Object} data - Same as {@link #initializeGraphState|data in initializeGraphState}.
- * @throws can throw the following error msg:
+ * @throws can throw the following error or warning msg:
  * INSUFFICIENT_DATA - msg if no nodes are provided
  * INVALID_LINKS - if links point to nonexistent nodes
+ * INSUFFICIENT_LINKS - if no links are provided
  * @returns {undefined}
  * @memberof Graph/helper
  */
@@ -216,6 +217,11 @@ function _validateGraphData(data) {
         throwErr("Graph", ERRORS.INSUFFICIENT_DATA);
     }
 
+    if (!data.links || !data.links.length) {
+        throwWarning("Graph", ERRORS.INSUFFICIENT_LINKS);
+        data.links = [];
+    }
+
     const n = data.links.length;
 
     for (let i = 0; i < n; i++) {

src/err.js

@@ -1,6 +1,8 @@
 /*eslint max-len: ["error", 200]*/
 export default {
     GRAPH_NO_ID_PROP: "id prop not defined! id property is mandatory and it should be unique.",
+    INSUFFICIENT_LINKS:
+        "you are passing invalid data to react-d3-graph. You must include a links array in the data object you're passing down to the <Graph> component.",
     INVALID_LINKS:
         "you provided a invalid links data structure. Links source and target attributes must point to an existent node",
     INSUFFICIENT_DATA:

src/utils.js

@@ -185,4 +185,17 @@ function throwErr(component, msg) {
     throw Error(error);
 }
 
-export { isDeepEqual, isEmptyObject, deepClone, merge, pick, antiPick, throwErr };
+/**
+ * Helper function for customized warning logging.
+ * @param  {string} component - the name of the component where the warning is to be thrown.
+ * @param  {string} msg - the message contain a more detailed explanation about the error.
+ * @returns {Warning} the thrown warning.
+ * @memberof utils
+ */
+function throwWarning(component, msg) {
+    const warning = `react-d3-graph :: ${component} :: ${msg}`;
+
+    console.warn(warning);
+}
+
+export { isDeepEqual, isEmptyObject, deepClone, merge, pick, antiPick, throwErr, throwWarning };