diff --git a/src/components/CustomTextArea.tsx b/src/components/CustomTextArea.tsx
index 4c2dc58..460efd4 100644
--- a/src/components/CustomTextArea.tsx
+++ b/src/components/CustomTextArea.tsx
@@ -42,7 +42,9 @@ function validateMapJsonStr(inStr: string, currentValidationState: ValidationSta
       const { name, meta, coordinates } = edge;
       if (
         !name || typeof(name) != 'string' ||
-        (!!meta && typeof(meta) != 'object') ||
+        !meta || typeof(meta) != 'object' ||
+        !meta.endpoint_identifiers || typeof(meta.endpoint_identifiers) != 'object' ||
+        !Array.isArray(meta.endpoint_identifiers?.names) ||
         !coordinates || !Array.isArray(coordinates) ||
         coordinates.some((coordinate) => {
           return !Array.isArray(coordinate)
diff --git a/test/react/CustomTextArea.spec.js b/test/react/CustomTextArea.spec.js
index bc433d8..a26cc5b 100644
--- a/test/react/CustomTextArea.spec.js
+++ b/test/react/CustomTextArea.spec.js
@@ -1,3 +1,4 @@
+import { update } from "lodash";
 import { CustomTextArea } from "../../src/testables.ts";
 import * as React from "react";
 import * as ReactDOM from "react-dom/client";
@@ -20,6 +21,64 @@ const inputTypes = [
     window.HTMLTextAreaElement,
 ];
 
+const emptyTopology = `
+    {
+        "nodes": [
+        ],
+        "edges": [
+        ]
+    }
+`.trim();
+
+function makeNodeJson(name) {
+    return `{
+        "name": "${name}",
+        "meta": {
+            "displayName": "",
+            "svg": "",
+            "template": ""
+        },
+        "coordinate": [
+            ${ 30 + Math.random() * 4},
+            -${ -90 + Math.random() * 5},
+        ]
+    }`;
+};
+
+function makeEdgeNameOnlyJson(nodeAName, nodeBName) {
+    return `{
+        "name": "${nodeAName}--${nodeBName}"
+    }`;
+};
+
+function makeMultilineEdgePartial(nodeA, nodeB) {
+    return `
+        "meta": {
+            "endpoint_identifiers": {
+                "names": [
+                    "${nodeA.name}",
+                    "${nodeB.name}"
+                ]
+            }
+        },
+        "coordinates": [
+            [
+                ${nodeA.coordinate[0]},
+                ${nodeA.coordinate[1]}
+            ],
+            [
+                ${(nodeA.coordinate[0] + nodeB.coordinate[0]) / 2},
+                ${(nodeA.coordinate[1] + nodeB.coordinate[1]) / 2}
+            ],
+            [
+                ${nodeB.coordinate[0]},
+                ${nodeB.coordinate[1]}
+            ],
+        ],
+        "children": []
+    `.trim();
+};
+
 // cribbed from https://stackoverflow.com/questions/23892547/what-is-the-best-way-to-trigger-change-or-input-event-in-react-js
 function triggerInputChange(node, value = '') {
     // only process the change on elements we know have a value setter in their constructor
@@ -64,4 +123,38 @@ describe("Component CustomTextArea esmap", () => {
 
         expect(error.innerText).toBeTruthy();
     })
+    it("should allow adding multiline pasting without resetting the form", async () => {
+        await act(async () => {
+            let elems = document.getElementsByTagName("textarea");
+            let elem = elems[0];
+            triggerInputChange(elem, emptyTopology);
+        });
+        expect(elem.innerText).toEqual(emptyTopology);
+
+        // TODO: complete test script
+        await act(async () => {
+            let startEditPos = elem.indexOf('"nodes": [');
+            for (edgeName of ["A", "B"]) {
+                const newNode = makeNodeJson(edgeName);
+                const newNodeLen = newNode.length;
+                let updatedText = `
+                    ${elem.innerText.substring(0, startEditPos)}
+                    ${newNode}
+                    ${elem.innerText.substring(startEditPos + newNodeLen)}
+                `.trim();
+                triggerInputChange(elem, updatedText);
+            }
+        });
+        await act(async () => {
+            const newEdge = makeEdgeNameOnlyJson("A", "B");
+            const newEdgeLen = newEdge.length;
+            let startEditPos = elem.indexOf('"edges": [');
+            let updatedText = `
+                ${elem.innerText.substring(0, startEditPos)}
+                ${newEdge}
+                ${elm.innerText.substring(startEditPos + newEdgeLen)}
+            `.trim();
+            triggerInputChange(elem, updatedText);
+        });
+    });
 })
\ No newline at end of file