web: use defaults; calculate table height

web/src/components/CaseBuilder/BusesTable.tsx

@@ -152,6 +152,12 @@ interface BusesTableProps {
   onBusRenamed: (oldName: string, newName: string) => ValidationError | null;
 }
 
+function computeBusesTableHeight(scenario: UnitCommitmentScenario): string {
+  const numBuses = Object.keys(scenario.Buses).length;
+  const height = 65 + Math.min(numBuses, 15) * 28;
+  return `${height}px`;
+}
+
 function BusesTable(props: BusesTableProps) {
   const tableContainerRef = useRef<HTMLDivElement | null>(null);
 
@@ -188,7 +194,7 @@ function BusesTable(props: BusesTableProps) {
       layout: "fitColumns",
       data: generateBusesTableData(scenario),
       columns: generateBusesTableColumns(scenario),
-      maxHeight: "500px",
+      height: computeBusesTableHeight(scenario),
     });
     table.on("cellEdited", (cell) => {
       onCellEdited(cell);

web/src/components/CaseBuilder/CaseBuilder.tsx

@@ -29,6 +29,7 @@ import {
   changeTimeHorizon,
   changeTimeStep,
 } from "../../core/Operations/parameterOperations";
+import { preprocess } from "../../core/Operations/preprocessing";
 
 const CaseBuilder = () => {
   const [scenario, setScenario] = useState(TEST_SCENARIO);
@@ -87,11 +88,16 @@ const CaseBuilder = () => {
   };
 
   const onLoad = (scenario: UnitCommitmentScenario) => {
-    if (!validate(scenario)) {
+    const preprocessed = preprocess(
+      scenario,
+    ) as unknown as UnitCommitmentScenario;
+
+    // Validate and assign default values
+    if (!validate(preprocessed)) {
       console.error(validate.errors);
       return;
     }
-    setScenario(scenario);
+    setScenario(preprocessed);
   };
 
   const onParameterChanged = (key: string, value: string) => {

web/src/core/Operations/preprocessing.test.ts

@@ -0,0 +1,39 @@
+/*
+ * UnitCommitment.jl: Optimization Package for Security-Constrained Unit Commitment
+ * Copyright (C) 2020-2025, UChicago Argonne, LLC. All rights reserved.
+ * Released under the modified BSD license. See COPYING.md for more details.
+ */
+
+import assert from "node:assert";
+import { preprocess } from "./preprocessing";
+
+export const PREPROCESSING_TEST_DATA_1: any = {
+  Parameters: {
+    Version: "0.4",
+    "Time horizon (h)": 5,
+  },
+  Buses: {
+    b1: { "Load (MW)": [35.79534, 34.38835, 33.45083, 32.89729, 33.25044] },
+    b2: { "Load (MW)": 10 },
+    b3: { "Load (MW)": [27.3729, 26.29698, 25.58005, 25.15675, 25.4268] },
+  },
+};
+
+test("preprocess", () => {
+  const newScenario = preprocess(PREPROCESSING_TEST_DATA_1);
+  assert.deepEqual(newScenario, {
+    Parameters: {
+      Version: "0.4",
+      "Time horizon (h)": 5,
+      "Power balance penalty ($/MW)": 1000,
+      "Scenario name": "s1",
+      "Scenario weight": 1,
+      "Time step (min)": 60,
+    },
+    Buses: {
+      b1: { "Load (MW)": [35.79534, 34.38835, 33.45083, 32.89729, 33.25044] },
+      b2: { "Load (MW)": [10, 10, 10, 10, 10] },
+      b3: { "Load (MW)": [27.3729, 26.29698, 25.58005, 25.15675, 25.4268] },
+    },
+  });
+});

web/src/core/Operations/preprocessing.ts

@@ -0,0 +1,34 @@
+// @ts-nocheck
+
+/*
+ * UnitCommitment.jl: Optimization Package for Security-Constrained Unit Commitment
+ * Copyright (C) 2020-2025, UChicago Argonne, LLC. All rights reserved.
+ * Released under the modified BSD license. See COPYING.md for more details.
+ */
+
+import { validate } from "../Validation/validate";
+
+export const preprocess = (data) => {
+  // Make a copy of the original data
+  let result = JSON.parse(JSON.stringify(data));
+
+  // Run JSON validation and assign default values
+  if (!validate(result)) {
+    console.error(validate.errors);
+    throw Error("Invalid JSON");
+  }
+
+  // Expand scalars into arrays
+  const timeHorizon = result["Parameters"]["Time horizon (h)"];
+  const timeStep = result["Parameters"]["Time step (min)"];
+  const T = (timeHorizon * 60) / timeStep;
+  for (const busName in result["Buses"]) {
+    // @ts-ignore
+    const busData = result["Buses"][busName];
+    const busLoad = busData["Load (MW)"];
+    if (typeof busLoad === "number") {
+      busData["Load (MW)"] = Array(T).fill(busLoad);
+    }
+  }
+  return result;
+};

web/src/core/Validation/validate.ts

@@ -9,6 +9,7 @@ import Ajv from "ajv";
 
 // Create Ajv instance with detailed debug options
 const ajv = new Ajv({
+  useDefaults: true,
   verbose: true,
   allErrors: true,
   $data: true,