diff --git a/.github/workflows/node.js.yml b/.github/workflows/node.js.yml
index a485cb6..e661396 100644
--- a/.github/workflows/node.js.yml
+++ b/.github/workflows/node.js.yml
@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-22.04
     strategy:
       matrix:
-        node-version: [12.x, 14.x, 16.x, 18.x, 20.x]
+        node-version: [12, 14, 16, 18, 20]
     steps:
     - uses: actions/checkout@v4
     - name: Use Node.js ${{ matrix.node-version }}
@@ -18,4 +18,8 @@ jobs:
       run: |
         sudo apt-get update
         sudo apt-get install -y build-essential libcairo2-dev libgif-dev libpango1.0-dev
-    - run: cd "$GITHUB_WORKSPACE"/export-server && npm install
+    - name: Install NPM packages
+      run: cd "$GITHUB_WORKSPACE"/export-server && npm install
+    - name: Tests
+      run: cd "$GITHUB_WORKSPACE"/export-server && ./test.sh
+      if: matrix.node-version >= 18
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 26279d9..2318222 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -37,6 +37,7 @@ node_18:
   script:
     - cd ./export-server
     - npm install
+    - ./test.sh
 
 node_20:
   image: node:20-slim
@@ -47,3 +48,4 @@ node_20:
   script:
     - cd ./export-server
     - npm install
+    - ./test.sh
diff --git a/export-server/test.sh b/export-server/test.sh
new file mode 100755
index 0000000..3130341
--- /dev/null
+++ b/export-server/test.sh
@@ -0,0 +1,30 @@
+#!/bin/sh
+
+# Start the server.
+npm run start &
+# Give server some time to start completely.
+sleep 3
+SERVER_PID=$(pgrep node)
+echo "Server process id is $SERVER_PID."
+
+# Run actual tests.
+node --test
+EXIT_CODE=$?
+
+# Stop / kill server process.
+kill $SERVER_PID
+if [ $? -ne 0 ]
+then
+  kill -9 $SERVER_PID
+fi
+
+sleep 1
+
+if [ $EXIT_CODE -eq 0 ]
+then
+  echo Tests were successful.
+  exit 0
+else
+  echo Tests have failed.
+  exit 1
+fi
diff --git a/export-server/tests/server.test.js b/export-server/tests/server.test.js
new file mode 100644
index 0000000..5634c62
--- /dev/null
+++ b/export-server/tests/server.test.js
@@ -0,0 +1,336 @@
+const assert = require('node:assert');
+const { spawn, spawnSync } = require('node:child_process');
+const http = require('node:http');
+const { after, before, describe, it } = require('node:test');
+
+describe('server', () => {
+  describe('request to non-root URL is not acceptable', () => {
+    it('HTTP status code 404 when another URL is requested', () => {
+      const options = {
+        port: 3000,
+        host: 'localhost',
+        method: 'POST',
+        path: '/foo.svg'
+      };
+
+      const req = http.request(options);
+      req.end();
+
+      req.on('response', (response) => {
+        assert.strictEqual(404, response.statusCode);
+      });
+    });
+  });
+
+  describe('only POST method is allowed', () => {
+    it('HTTP status code 405 when DELETE is used', () => {
+      const options = {
+        port: 3000,
+        host: 'localhost',
+        method: 'DELETE',
+      };
+
+      const req = http.request(options);
+      req.end();
+
+      req.on('response', (response) => {
+        assert.strictEqual(405, response.statusCode);
+        assert.ok(response.headers['allow']);
+        assert.strictEqual(response.headers['allow'], 'POST');
+      });
+    });
+
+    it('HTTP status code 405 when GET is used', () => {
+      const options = {
+        port: 3000,
+        host: 'localhost',
+        method: 'GET',
+      };
+
+      const req = http.request(options);
+      req.end();
+
+      req.on('response', (response) => {
+        assert.strictEqual(405, response.statusCode);
+        assert.ok(response.headers['allow']);
+        assert.strictEqual(response.headers['allow'], 'POST');
+      });
+    });
+
+    it('HTTP status code 405 when HEAD is used', () => {
+      const options = {
+        port: 3000,
+        host: 'localhost',
+        method: 'HEAD',
+      };
+
+      const req = http.request(options);
+      req.end();
+
+      req.on('response', (response) => {
+        assert.strictEqual(405, response.statusCode);
+        assert.ok(response.headers['allow']);
+        assert.strictEqual(response.headers['allow'], 'POST');
+      });
+    });
+
+    it('HTTP status code 405 when PATCH is used', () => {
+      const options = {
+        port: 3000,
+        host: 'localhost',
+        method: 'PATCH',
+      };
+
+      const req = http.request(options);
+      req.end();
+
+      req.on('response', (response) => {
+        assert.strictEqual(405, response.statusCode);
+        assert.ok(response.headers['allow']);
+        assert.strictEqual(response.headers['allow'], 'POST');
+      });
+    });
+
+    it('HTTP status code 405 when PUT is used', () => {
+      const options = {
+        port: 3000,
+        host: 'localhost',
+        method: 'PUT',
+      };
+
+      const req = http.request(options);
+      req.end();
+
+      req.on('response', (response) => {
+        assert.strictEqual(405, response.statusCode);
+        assert.ok(response.headers['allow']);
+        assert.strictEqual(response.headers['allow'], 'POST');
+      });
+    });
+
+    it('HTTP status code 405 when TRACE is used', () => {
+      const options = {
+        port: 3000,
+        host: 'localhost',
+        method: 'TRACE',
+      };
+
+      const req = http.request(options);
+      req.end();
+
+      req.on('response', (response) => {
+        assert.strictEqual(405, response.statusCode);
+        assert.ok(response.headers['allow']);
+        assert.strictEqual(response.headers['allow'], 'POST');
+      });
+    });
+  });
+
+  describe('query available methods via OPTIONS', () => {
+    it('HTTP status code 204 and Allow header for OPTIONS', () => {
+      const options = {
+        port: 3000,
+        host: 'localhost',
+        method: 'OPTIONS',
+      };
+
+      const req = http.request(options);
+      req.end();
+
+      req.on('response', (response) => {
+        // 204: no content
+        assert.strictEqual(204, response.statusCode);
+        // Response shall contain header "Allow: POST".
+        assert.ok(response.headers['allow']);
+        assert.strictEqual(response.headers['allow'], 'POST');
+      });
+    });
+  });
+
+  describe('large payload is rejected', () => {
+    it('HTTP status code 413 when request is too large', () => {
+      const options = {
+        port: 3000,
+        host: 'localhost',
+        method: 'POST',
+      };
+
+      const req = http.request(options);
+      const payload = { long: 'abcdefghij'.repeat(500000) };
+      req.write(JSON.stringify(payload));
+      req.end();
+
+      req.on('response', (response) => {
+        assert.strictEqual(413, response.statusCode);
+      });
+    });
+  });
+
+  describe('malformed JSON is rejected', () => {
+    it('HTTP status code 400 when request contains invalid JSON', () => {
+      const options = {
+        port: 3000,
+        host: 'localhost',
+        method: 'POST',
+      };
+
+      const req = http.request(options);
+      const payload = '{ "foo": "bar", "baz": ';
+      req.write(payload);
+      req.end();
+
+      req.on('response', (response) => {
+        assert.strictEqual(400, response.statusCode);
+      });
+    });
+  });
+
+  describe('image generation requests', () => {
+    const example_data = {
+      title: {
+        text: "ECharts entry example"
+      },
+      tooltip: {},
+      legend: {
+        data: ["Sales"]
+      },
+      backgroundColor: "#ffffff",
+      xAxis: {
+        data: ["shirt","cardigan","chiffon shirt","pants","heels","socks"]
+      },
+      yAxis: {},
+      series: [{
+        name: "Sales",
+        type: "bar",
+        data: [5,20,36,10,10,20]
+      }]
+    };
+    const payload = JSON.stringify(example_data);
+
+    it('request with example data is successful', () => {
+      const options = {
+        port: 3000,
+        host: 'localhost',
+        method: 'POST',
+        headers: {
+          'X-Image-Format': 'svg'
+        }
+      };
+
+      const req = http.request(options);
+      req.write(payload);
+      req.end();
+
+      req.on('response', (response) => {
+        assert.strictEqual(200, response.statusCode);
+        let body = '';
+        response.on('data', (chunk) => {
+          body += chunk;
+        });
+        response.on('end', () => {
+          assert.ok(body.startsWith('<svg'));
+          assert.ok(body.endsWith('</svg>'));
+          assert.ok(body.indexOf('width="700"') > 0);
+          assert.ok(body.indexOf('height="400"') > 0);
+          assert.ok(body.indexOf('ECharts entry example') > 0);
+          assert.ok(body.indexOf('cardigan') > 0);
+          assert.ok(body.indexOf('chiffon shirt') > 0);
+          assert.ok(body.indexOf('pants') > 0);
+          assert.ok(body.indexOf('heels') > 0);
+          assert.ok(body.indexOf('socks') > 0);
+        });
+      });
+    });
+
+    it('request with different image width', () => {
+      const options = {
+        port: 3000,
+        host: 'localhost',
+        method: 'POST',
+        headers: {
+          'X-Image-Format': 'svg',
+          'X-Image-Width': '751'
+        }
+      };
+
+      const req = http.request(options);
+      req.write(payload);
+      req.end();
+
+      req.on('response', (response) => {
+        assert.strictEqual(200, response.statusCode);
+        let body = '';
+        response.on('data', (chunk) => {
+          body += chunk;
+        });
+        response.on('end', () => {
+          assert.ok(body.startsWith('<svg'));
+          assert.ok(body.endsWith('</svg>'));
+          assert.ok(body.indexOf('width="751"') > 0);
+          assert.ok(body.indexOf('height="400"') > 0);
+        });
+      });
+    });
+
+    it('request with different image height', () => {
+      const options = {
+        port: 3000,
+        host: 'localhost',
+        method: 'POST',
+        headers: {
+          'X-Image-Format': 'svg',
+          'X-Image-Height': '432'
+        }
+      };
+
+      const req = http.request(options);
+      req.write(payload);
+      req.end();
+
+      req.on('response', (response) => {
+        assert.strictEqual(200, response.statusCode);
+        let body = '';
+        response.on('data', (chunk) => {
+          body += chunk;
+        });
+        response.on('end', () => {
+          assert.ok(body.startsWith('<svg'));
+          assert.ok(body.endsWith('</svg>'));
+          assert.ok(body.indexOf('width="700"') > 0);
+          assert.ok(body.indexOf('height="432"') > 0);
+        });
+      });
+    });
+
+    it('request with different image width and height', () => {
+      const options = {
+        port: 3000,
+        host: 'localhost',
+        method: 'POST',
+        headers: {
+          'X-Image-Format': 'svg',
+          'X-Image-Width': '765',
+          'X-Image-Height': '456'
+        }
+      };
+
+      const req = http.request(options);
+      req.write(payload);
+      req.end();
+
+      req.on('response', (response) => {
+        assert.strictEqual(200, response.statusCode);
+        let body = '';
+        response.on('data', (chunk) => {
+          body += chunk;
+        });
+        response.on('end', () => {
+          assert.ok(body.startsWith('<svg'));
+          assert.ok(body.endsWith('</svg>'));
+          assert.ok(body.indexOf('width="765"') > 0);
+          assert.ok(body.indexOf('height="456"') > 0);
+        });
+      });
+    });
+  });
+});