Preserve jsonb number representation in the JSON editor (#9854)

docs/en_US/release_notes_9_16.rst

@@ -43,6 +43,7 @@ Bug fixes
   | `Issue #9595 <https://github.com/pgadmin-org/pgadmin4/issues/9595>`_ -  Fix missing ALTER ... SET DEFAULT statements for inherited columns in the generated table SQL/EDIT script.
   | `Issue #9677 <https://github.com/pgadmin-org/pgadmin4/issues/9677>`_ -  Fix the Unlogged table toggle in table properties not generating any ALTER TABLE ... SET LOGGED/UNLOGGED statement.
   | `Issue #9828 <https://github.com/pgadmin-org/pgadmin4/issues/9828>`_ -  Fix tool calls failing against OpenAI-compatible providers that emit empty/null name, arguments, or id fields in streaming continuation deltas.
+  | `Issue #9854 <https://github.com/pgadmin-org/pgadmin4/issues/9854>`_ -  Fix the JSON editor stripping trailing fractional zeros (e.g. 10.00) and rewriting large integers in jsonb values, which corrupted unmodified numbers when saving.
   | `Issue #9875 <https://github.com/pgadmin-org/pgadmin4/issues/9875>`_ -  Fixed an issue where EXPLAIN and EXPLAIN ANALYZE failed to execute when blank lines separated clauses in the SQL query.
   | `Issue #9810 <https://github.com/pgadmin-org/pgadmin4/issues/9810>`_ -  Use the ServerManager's passfile for the credential gate in connect() so the check matches the passfile actually used for the connection, and warn on conflicting passfile/passexec settings.
   | `Issue #9892 <https://github.com/pgadmin-org/pgadmin4/issues/9892>`_ -  Fix blank difference counts on the top-level group rows in Schema Diff.

web/package.json

@@ -117,6 +117,7 @@
     "json-bignumber": "^1.1.1",
     "leaflet": "^1.9.4",
     "lodash": "4.*",
+    "lossless-json": "^4.3.0",
     "marked": "^18.0.2",
     "moment": "^2.30.1",
     "moment-timezone": "^0.6.2",

web/pgadmin/static/js/components/JsonEditor.jsx

@@ -30,7 +30,12 @@ export default function JsonEditor({setJsonEditorSize, value, options, className
         ...defaultOptions,
         ...options,
         onChange: (updatedContent) => {
-          options.onChange(currentMode.current == 'text' ? updatedContent.text : JSON.stringify(updatedContent.json));
+          // Serialize non-text modes (tree/table) with the configured parser
+          // so a lossless parser preserves the original number representation
+          // (big integers, trailing fractional zeros) instead of being
+          // rewritten by the native JSON serializer.
+          const serializer = options.parser ?? JSON;
+          options.onChange(currentMode.current == 'text' ? updatedContent.text : serializer.stringify(updatedContent.json));
           options.onValidationError(editor.current.validate());
         },
         onChangeMode: (mode) => {

web/pgadmin/tools/sqleditor/static/js/components/QueryToolDataGrid/Editors.jsx

@@ -13,7 +13,7 @@ import { DefaultButton, PrimaryButton } from '../../../../../../static/js/compon
 import CheckRoundedIcon from '@mui/icons-material/CheckRounded';
 import CloseIcon from '@mui/icons-material/Close';
 import gettext from 'sources/gettext';
-import JSONBigNumber from 'json-bignumber';
+import { losslessJSONParser, prettifyJSONString, prettifyJSONValue } from './json_utils';
 import JsonEditor from '../../../../../../static/js/components/JsonEditor';
 import PropTypes from 'prop-types';
 import { RowInfoContext } from '.';
@@ -394,13 +394,17 @@ export function JsonTextEditor({row, column, onRowChange, onClose}) {
 
   const value = React.useMemo(()=>{
     let newVal = row[column.key] ?? null;
-    /* If jsonb or array */
+    /* If jsonb or array. Pretty-print with a lossless JSON parser so that the
+     * original numeric representation (e.g. big integers and trailing
+     * fractional zeros like 10.00) is preserved. A plain JSON.parse/stringify
+     * round-trip would silently rewrite such numbers and corrupt unmodified
+     * values on save (#9854). */
     if(column.column_type_internal === 'jsonb' && !Array.isArray(newVal) && newVal != null) {
-      newVal = JSONBigNumber.stringify(JSONBigNumber.parse(newVal), null, 2);
+      newVal = prettifyJSONString(newVal);
     } else if (Array.isArray(newVal)) {
       let temp = newVal.map((ele)=>{
         if (typeof ele === 'object') {
-          return JSONBigNumber.stringify(ele, null, 2);
+          return prettifyJSONValue(ele);
         }
         return ele;
       });
@@ -456,6 +460,7 @@ export function JsonTextEditor({row, column, onRowChange, onClose}) {
           setJsonEditorSize={setJsonEditorSize}
           value={localVal??''}
           options={{
+            parser: losslessJSONParser,
             onChange: onChange,
             onValidationError: (errors)=>{setHasError(Boolean(errors));}
           }}

web/pgadmin/tools/sqleditor/static/js/components/QueryToolDataGrid/json_utils.js

@@ -0,0 +1,33 @@
+/////////////////////////////////////////////////////////////
+//
+// pgAdmin 4 - PostgreSQL Tools
+//
+// Copyright (C) 2013 - 2026, The pgAdmin Development Team
+// This software is released under the PostgreSQL Licence
+//
+//////////////////////////////////////////////////////////////
+
+import * as LosslessJSON from 'lossless-json';
+
+// A lossless JSON parser, with the same { parse, stringify } interface as the
+// native JSON object. It preserves the original numeric representation of a
+// value - including big integers and trailing fractional zeros such as 10.00 -
+// instead of normalizing it the way JSON.parse/JSON.stringify does.
+//
+// This matters for the JSON cell editor: jsonb values arrive from the server
+// as their canonical text, and a normalizing round-trip would silently rewrite
+// numbers (e.g. 10.00 -> 10), corrupting unmodified values when the document is
+// saved back. See issue #9854.
+export const losslessJSONParser = LosslessJSON;
+
+// Pretty-print a JSON string for the editor, preserving the exact numeric
+// representation of every value.
+export function prettifyJSONString(value) {
+  return LosslessJSON.stringify(LosslessJSON.parse(value), null, 2);
+}
+
+// Pretty-print an already-parsed JSON value (e.g. an element of an array
+// column) for the editor.
+export function prettifyJSONValue(value) {
+  return LosslessJSON.stringify(value, null, 2);
+}

web/regression/javascript/sqleditor/json_utils.spec.js

@@ -0,0 +1,53 @@
+/////////////////////////////////////////////////////////////
+//
+// pgAdmin 4 - PostgreSQL Tools
+//
+// Copyright (C) 2013 - 2026, The pgAdmin Development Team
+// This software is released under the PostgreSQL Licence
+//
+//////////////////////////////////////////////////////////////
+
+import {
+  losslessJSONParser,
+  prettifyJSONString,
+  prettifyJSONValue,
+} from '../../../pgadmin/tools/sqleditor/static/js/components/QueryToolDataGrid/json_utils';
+
+describe('QueryToolDataGrid json_utils', () => {
+  describe('prettifyJSONString', () => {
+    it('preserves trailing fractional zeros (#9854)', () => {
+      // A native JSON.parse/stringify round-trip would turn 10.00 into 10.
+      expect(prettifyJSONString('10.00')).toBe('10.00');
+      expect(prettifyJSONString('{"a":10.00,"b":3.140}')).toBe(
+        '{\n  "a": 10.00,\n  "b": 3.140\n}'
+      );
+    });
+
+    it('preserves big integers beyond Number precision', () => {
+      expect(prettifyJSONString('{"id":1234567890123456789}')).toBe(
+        '{\n  "id": 1234567890123456789\n}'
+      );
+    });
+
+    it('pretty-prints with two-space indentation', () => {
+      expect(prettifyJSONString('{"a":[1,2]}')).toBe(
+        '{\n  "a": [\n    1,\n    2\n  ]\n}'
+      );
+    });
+  });
+
+  describe('prettifyJSONValue', () => {
+    it('pretty-prints an already-parsed value', () => {
+      expect(prettifyJSONValue({ a: 1 })).toBe('{\n  "a": 1\n}');
+    });
+  });
+
+  describe('losslessJSONParser', () => {
+    it('exposes a JSON-compatible parse/stringify interface', () => {
+      expect(typeof losslessJSONParser.parse).toBe('function');
+      expect(typeof losslessJSONParser.stringify).toBe('function');
+      // Round-trips a trailing-zero number without normalizing it.
+      expect(losslessJSONParser.stringify(losslessJSONParser.parse('10.50'))).toBe('10.50');
+    });
+  });
+});

web/yarn.lock

@@ -10286,6 +10286,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"lossless-json@npm:^4.3.0":
+  version: 4.3.0
+  resolution: "lossless-json@npm:4.3.0"
+  checksum: 10c0/b561eb7f77ef99dbaa0df32fa2407ddcc2c61a0d53297240f0fdd6c2e5f2e0f7d224fb055f84e76467f5ec65547540662c265fcf7a1705497a2d44e323c517df
+  languageName: node
+  linkType: hard
+
 "lower-case@npm:^2.0.2":
   version: 2.0.2
   resolution: "lower-case@npm:2.0.2"
@@ -13052,6 +13059,7 @@ __metadata:
     leaflet: "npm:^1.9.4"
     loader-utils: "npm:^3.3.1"
     lodash: "npm:4.*"
+    lossless-json: "npm:^4.3.0"
     marked: "npm:^18.0.2"
     mini-css-extract-plugin: "npm:^2.10.2"
     moment: "npm:^2.30.1"