InfluxDB: Fix interpolation for floating point number values (#86396)

return number as it is

public/app/plugins/datasource/influxdb/datasource.test.ts

@@ -508,6 +508,22 @@ describe('InfluxDataSource Frontend Mode', () => {
         const expectation = `(\\/special\\/path|\\/some\\/other\\/path)`;
         expect(result).toBe(expectation);
       });
+
+      it('should return floating point number as it is', () => {
+        const variableMock = queryBuilder()
+          .withId('tempVar')
+          .withName('tempVar')
+          .withMulti(false)
+          .withOptions({
+            text: `1.0`,
+            value: `1.0`,
+          })
+          .build();
+        const value = `1.0`;
+        const result = ds.interpolateQueryExpr(value, variableMock, `select value / $tempVar from /^measurement$/`);
+        const expectation = `1.0`;
+        expect(result).toBe(expectation);
+      });
     });
   });
 });

public/app/plugins/datasource/influxdb/datasource.ts

@@ -315,6 +315,13 @@ export default class InfluxDatasource extends DataSourceWithBackend<InfluxQuery,
       return value;
     }
 
+    if (typeof value === 'string') {
+      // Check the value is a number. If not run to escape special characters
+      if (!isNaN(parseFloat(value))) {
+        return value;
+      }
+    }
+
     // If template variable is a multi-value variable
     // we always want to deal with special chars.
     if (variable.multi) {