feat(mcp-function) : add generateAreaChartTool to create area chart

__tests__/integration.spec.ts

@@ -291,7 +291,7 @@ describe("integration tests", () => {
 
     it("should have all tools properly exported", () => {
       // Verify that the total number of tools is correct
-      expect(tools).toHaveLength(17);
+      expect(tools).toHaveLength(18);
 
       // Define the expected list of tool names
       const expectedToolNames = [
@@ -312,6 +312,7 @@ describe("integration tests", () => {
         "generate_graph_chart",
         "generate_parallel_chart",
         "generate_tree_chart",
+        "generate_area_chart",
       ];
 
       // Verify that the actual exported tool names match expectations

__tests__/tools/area.spec.ts

@@ -0,0 +1,82 @@
+import { describe, expect, it } from "vitest";
+import { generateAreaChartTool } from "../../src/tools/area";
+import "../utils/matcher";
+
+describe("Area Chart Tool", () => {
+  it("should generate a basic area chart", async () => {
+    const result = await generateAreaChartTool.run({
+      data: [
+        { time: "2015", value: 23 },
+        { time: "2016", value: 32 },
+        { time: "2017", value: 28 },
+        { time: "2018", value: 45 },
+        { time: "2019", value: 38 },
+        { time: "2020", value: 52 },
+      ],
+      title: "Basic Area Chart",
+      width: 600,
+      height: 400,
+    });
+
+    await expect(result).toImageEqual("area-basic");
+  });
+
+  it("should generate a stacked area chart", async () => {
+    const result = await generateAreaChartTool.run({
+      data: [
+        { group: "Series A", time: "2015", value: 23 },
+        { group: "Series A", time: "2016", value: 32 },
+        { group: "Series A", time: "2017", value: 28 },
+        { group: "Series B", time: "2015", value: 18 },
+        { group: "Series B", time: "2016", value: 25 },
+        { group: "Series B", time: "2017", value: 22 },
+      ],
+      title: "Stacked Area Chart",
+      stack: true,
+      width: 600,
+      height: 400,
+    });
+
+    await expect(result).toImageEqual("area-stacked");
+  });
+
+  it("should generate an area chart with custom styling", async () => {
+    const result = await generateAreaChartTool.run({
+      data: [
+        { time: "Q1", value: 100 },
+        { time: "Q2", value: 150 },
+        { time: "Q3", value: 120 },
+        { time: "Q4", value: 180 },
+      ],
+      title: "Custom Styled Area Chart",
+      width: 800,
+      height: 500,
+      theme: "dark",
+      style: {
+        backgroundColor: "#1a1a1a",
+        palette: ["#ff6b6b", "#4ecdc4", "#45b7d1"],
+      },
+    });
+
+    await expect(result).toImageEqual("area-custom");
+  });
+
+  it("should generate area chart with smooth curves", async () => {
+    const result = await generateAreaChartTool.run({
+      data: [
+        { time: "Jan", value: 10 },
+        { time: "Feb", value: 25 },
+        { time: "Mar", value: 15 },
+        { time: "Apr", value: 35 },
+        { time: "May", value: 20 },
+        { time: "Jun", value: 40 },
+      ],
+      title: "Smooth Area Chart",
+      smooth: true,
+      width: 600,
+      height: 400,
+    });
+
+    await expect(result).toImageEqual("area-smooth");
+  });
+});

__tests__/tools/index.spec.ts

@@ -11,9 +11,9 @@ describe("tools index", () => {
    * Tool count validation
    * Validates that the total number of exported tools meets expectations (17 chart tools)
    */
-  it("should export all 17 chart tools", () => {
+  it("should export all 18 chart tools", () => {
     // Validate that the tools array contains 17 chart tools
-    expect(tools).toHaveLength(17);
+    expect(tools).toHaveLength(18);
   });
 
   /**
@@ -74,6 +74,7 @@ describe("tools index", () => {
       "generate_graph_chart", // Graph chart
       "generate_parallel_chart", // Parallel coordinates chart
       "generate_tree_chart", // Tree chart
+      "generate_area_chart", // Area chart
     ];
 
     // Get actual tool names and sort them

package.json

@@ -1,7 +1,7 @@
 {
   "name": "mcp-echarts",
   "description": "❤️ Generate visual charts using Apache ECharts with AI MCP dynamically.",
-  "version": "0.6.1",
+  "version": "0.7.0",
   "main": "build/index.js",
   "scripts": {
     "test": "vitest",

src/tools/area.ts

@@ -0,0 +1,49 @@
+import { z } from "zod";
+import { generateLineChartTool } from "./line";
+
+// Extends generateLineChartTool implementation since area charts are line charts with area fill enabled
+export const generateAreaChartTool = {
+  ...generateLineChartTool,
+  name: "generate_area_chart",
+  description:
+    "Generate an area chart to show data trends under continuous independent variables and observe the overall data trend, such as, displacement = velocity (average or instantaneous) × time: s = v × t. If the x-axis is time (t) and the y-axis is velocity (v) at each moment, an area chart allows you to observe the trend of velocity over time and infer the distance traveled by the area's size.",
+  inputSchema: generateLineChartTool.inputSchema.extend({
+    data: z
+      .array(
+        z.object({
+          group: z
+            .string()
+            .optional()
+            .describe(
+              "Group name for multiple series, required when stack is enabled",
+            ),
+          time: z.string(),
+          value: z.number(),
+        }),
+      )
+      .describe(
+        "Data for area chart, such as, [{ time: '2015', value: 23 }, { time: '2016', value: 32 }]. For multiple series: [{ group: 'Series A', time: '2015', value: 23 }, { group: 'Series B', time: '2015', value: 18 }].",
+      )
+      .nonempty({ message: "Area chart data cannot be empty." }),
+  }),
+  run: (params: {
+    axisXTitle?: string;
+    axisYTitle?: string;
+    data: Array<{ time: string; value: number; group?: string }>;
+    height: number;
+    showArea?: boolean;
+    showSymbol?: boolean;
+    smooth?: boolean;
+    stack?: boolean;
+    theme?: "default" | "dark";
+    title?: string;
+    width: number;
+    outputType?: "png" | "svg" | "option";
+  }) => {
+    // Force showArea to true for area chart
+    return generateLineChartTool.run({
+      ...params,
+      showArea: true,
+    });
+  },
+};

src/tools/index.ts

@@ -1,3 +1,4 @@
+import { generateAreaChartTool } from "./area";
 import { generateBarChartTool } from "./bar";
 import { generateBoxplotChartTool } from "./boxplot";
 import { generateCandlestickChartTool } from "./candlestick";
@@ -18,6 +19,7 @@ import { generateTreemapChartTool } from "./treemap";
 
 export const tools = [
   generateEChartsTool,
+  generateAreaChartTool,
   generateLineChartTool,
   generateBarChartTool,
   generatePieChartTool,
@@ -39,6 +41,7 @@ export const tools = [
 // Re-export individual tools for convenient use in tests and other places
 export {
   generateEChartsTool,
+  generateAreaChartTool,
   generateLineChartTool,
   generateBarChartTool,
   generatePieChartTool,