diff --git a/.gitea/workflows/ci.yml b/.gitea/workflows/ci.yml
index 1c1caa2..a45fdca 100644
--- a/.gitea/workflows/ci.yml
+++ b/.gitea/workflows/ci.yml
@@ -49,8 +49,11 @@ jobs:
         with:
           node-version: "22"
 
-      - name: 의존성 설치 + 빌드
-        run: |
-          cd frontend
-          npm ci
-          npm run build
+      - name: 의존성 설치
+        run: cd frontend && npm ci
+
+      - name: 프론트 테스트 (vitest)
+        run: cd frontend && npm test
+
+      - name: 프론트 빌드 (JSX 오류·깨진 import 검출)
+        run: cd frontend && npm run build
diff --git a/frontend/package-lock.json b/frontend/package-lock.json
index 37b3336..2926988 100644
--- a/frontend/package-lock.json
+++ b/frontend/package-lock.json
@@ -16,7 +16,8 @@
       },
       "devDependencies": {
         "@vitejs/plugin-react": "^4.3.4",
-        "vite": "^6.0.7"
+        "vite": "^6.0.7",
+        "vitest": "^4.1.10"
       }
     },
     "node_modules/@babel/code-frame": {
@@ -1189,6 +1190,13 @@
         "win32"
       ]
     },
+    "node_modules/@standard-schema/spec": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/@standard-schema/spec/-/spec-1.1.0.tgz",
+      "integrity": "sha512-l2aFy5jALhniG5HgqrD6jXLi/rUWrKvqN/qJx6yoJsgKhblVd+iqqU4RCXavm/jPityDo5TCvKMnpjKnOriy0w==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/@types/babel__core": {
       "version": "7.20.5",
       "resolved": "https://registry.npmjs.org/@types/babel__core/-/babel__core-7.20.5.tgz",
@@ -1234,6 +1242,24 @@
         "@babel/types": "^7.28.2"
       }
     },
+    "node_modules/@types/chai": {
+      "version": "5.2.3",
+      "resolved": "https://registry.npmjs.org/@types/chai/-/chai-5.2.3.tgz",
+      "integrity": "sha512-Mw558oeA9fFbv65/y4mHtXDs9bPnFMZAL/jxdPFUpOHHIXX91mcgEHbS5Lahr+pwZFR8A7GQleRWeI6cGFC2UA==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/deep-eql": "*",
+        "assertion-error": "^2.0.1"
+      }
+    },
+    "node_modules/@types/deep-eql": {
+      "version": "4.0.2",
+      "resolved": "https://registry.npmjs.org/@types/deep-eql/-/deep-eql-4.0.2.tgz",
+      "integrity": "sha512-c9h9dVVMigMPc4bwTvC5dxqtqJZwQPePsWjPlpSOnojbor6pGqdk541lfA7AqFQr5pB1BRdq0juY9db81BwyFw==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/@types/estree": {
       "version": "1.0.9",
       "resolved": "https://registry.npmjs.org/@types/estree/-/estree-1.0.9.tgz",
@@ -1262,6 +1288,119 @@
         "vite": "^4.2.0 || ^5.0.0 || ^6.0.0 || ^7.0.0"
       }
     },
+    "node_modules/@vitest/expect": {
+      "version": "4.1.10",
+      "resolved": "https://registry.npmjs.org/@vitest/expect/-/expect-4.1.10.tgz",
+      "integrity": "sha512-YsCn+qAk1GWjQOWFEsEcL2gNQ0zmVmQu3T03qP6UyjhtmdtwtbuI+DASn/7iQB3HGTXkdBwGddzxPlmiql5vlA==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@standard-schema/spec": "^1.1.0",
+        "@types/chai": "^5.2.2",
+        "@vitest/spy": "4.1.10",
+        "@vitest/utils": "4.1.10",
+        "chai": "^6.2.2",
+        "tinyrainbow": "^3.1.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/@vitest/mocker": {
+      "version": "4.1.10",
+      "resolved": "https://registry.npmjs.org/@vitest/mocker/-/mocker-4.1.10.tgz",
+      "integrity": "sha512-v0xaezt+DKEmKfaxg133ldzADrwLGd7Ze1MfQQTYfvs8OqZIwbxyxaYURivwV7sWy5fqn3rH5uOrSp07bp44Ow==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@vitest/spy": "4.1.10",
+        "estree-walker": "^3.0.3",
+        "magic-string": "^0.30.21"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      },
+      "peerDependencies": {
+        "msw": "^2.4.9",
+        "vite": "^6.0.0 || ^7.0.0 || ^8.0.0"
+      },
+      "peerDependenciesMeta": {
+        "msw": {
+          "optional": true
+        },
+        "vite": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@vitest/pretty-format": {
+      "version": "4.1.10",
+      "resolved": "https://registry.npmjs.org/@vitest/pretty-format/-/pretty-format-4.1.10.tgz",
+      "integrity": "sha512-W1HsjSH4MXQ9YfmmhLAoIYf1HRfekQCGngeIgcei6MP5QQGWUe0gkopdZQaVCFO+JDJMrAJGwa5pRpNpvy4P8Q==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "tinyrainbow": "^3.1.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/@vitest/runner": {
+      "version": "4.1.10",
+      "resolved": "https://registry.npmjs.org/@vitest/runner/-/runner-4.1.10.tgz",
+      "integrity": "sha512-IKI6kpIH+LmpROplyLwBBaCfMgOZOMsygVa6BARD6ahA04VRuJSa6OaVG7kRvSEMD870Vd91rSSw0eegtWyLGg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@vitest/utils": "4.1.10",
+        "pathe": "^2.0.3"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/@vitest/snapshot": {
+      "version": "4.1.10",
+      "resolved": "https://registry.npmjs.org/@vitest/snapshot/-/snapshot-4.1.10.tgz",
+      "integrity": "sha512-xRkfOT1qpTAi/Ti4Y1LtfRc3kEuqxGw59eN2jN9pRWMtS/XDevekhcFSqvQqjUNGksfjMJu3Y+oJ+4Ypn2OaJw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@vitest/pretty-format": "4.1.10",
+        "@vitest/utils": "4.1.10",
+        "magic-string": "^0.30.21",
+        "pathe": "^2.0.3"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/@vitest/spy": {
+      "version": "4.1.10",
+      "resolved": "https://registry.npmjs.org/@vitest/spy/-/spy-4.1.10.tgz",
+      "integrity": "sha512-PLf/Ugvoq5wO/b4rwYCR1h2PSIdXz7wnkQFMiUpLdtM7l6pqVFcQIBEHyT1+l+cj7mNwAfZHzqXqDyjvOuwbDw==",
+      "dev": true,
+      "license": "MIT",
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/@vitest/utils": {
+      "version": "4.1.10",
+      "resolved": "https://registry.npmjs.org/@vitest/utils/-/utils-4.1.10.tgz",
+      "integrity": "sha512-fy9am/HWxbaGt/Sawrp90vt6Y6jQwf1RX77cz3uwoJwJVMli/e1IEwRPnMNJ7vKfPTwo0diXifkpPvwH9v7nGA==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@vitest/pretty-format": "4.1.10",
+        "convert-source-map": "^2.0.0",
+        "tinyrainbow": "^3.1.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
     "node_modules/agent-base": {
       "version": "6.0.2",
       "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-6.0.2.tgz",
@@ -1274,6 +1413,16 @@
         "node": ">= 6.0.0"
       }
     },
+    "node_modules/assertion-error": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/assertion-error/-/assertion-error-2.0.1.tgz",
+      "integrity": "sha512-Izi8RQcffqCeNVgFigKli1ssklIbpHnCYc6AknXGYoB6grJqyeby7jv12JUQgmTAnIDnbck1uxksT4dzN3PWBA==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=12"
+      }
+    },
     "node_modules/asynckit": {
       "version": "0.4.0",
       "resolved": "https://registry.npmjs.org/asynckit/-/asynckit-0.4.0.tgz",
@@ -1373,6 +1522,16 @@
       ],
       "license": "CC-BY-4.0"
     },
+    "node_modules/chai": {
+      "version": "6.2.2",
+      "resolved": "https://registry.npmjs.org/chai/-/chai-6.2.2.tgz",
+      "integrity": "sha512-NUPRluOfOiTKBKvWPtSD4PhFvWCqOi0BGStNWs57X9js7XGTprSmFoz5F0tWhR4WPjNeR9jXqdC7/UpSJTnlRg==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      }
+    },
     "node_modules/combined-stream": {
       "version": "1.0.8",
       "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-1.0.8.tgz",
@@ -1470,6 +1629,13 @@
         "node": ">= 0.4"
       }
     },
+    "node_modules/es-module-lexer": {
+      "version": "2.3.1",
+      "resolved": "https://registry.npmjs.org/es-module-lexer/-/es-module-lexer-2.3.1.tgz",
+      "integrity": "sha512-shc1dbU90Yl/xq1QrC7QRtfcwURZuVRfPhZbDoldJ1cn1gzDvBaBWlv0eFolj5+0znnPJz5TXLxsN77X/12KTA==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/es-object-atoms": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/es-object-atoms/-/es-object-atoms-1.1.2.tgz",
@@ -1549,6 +1715,26 @@
         "node": ">=6"
       }
     },
+    "node_modules/estree-walker": {
+      "version": "3.0.3",
+      "resolved": "https://registry.npmjs.org/estree-walker/-/estree-walker-3.0.3.tgz",
+      "integrity": "sha512-7RUKfXgSMMkzt6ZuXmqapOurLGPPfgj6l9uRZ7lRGolvk0y2yocc35LdcxKC5PQZdn2DMqioAQ2NoWcrTKmm6g==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/estree": "^1.0.0"
+      }
+    },
+    "node_modules/expect-type": {
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/expect-type/-/expect-type-1.4.0.tgz",
+      "integrity": "sha512-KfYbmpRm0VbLjEvVa9yGwCi9GI34xvi7A/HXYWQO65CSD2u3MczUJSuwXKFIxlGsgBQizV9q5J9NHj4VG0n+pA==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "engines": {
+        "node": ">=12.0.0"
+      }
+    },
     "node_modules/fdir": {
       "version": "6.5.0",
       "resolved": "https://registry.npmjs.org/fdir/-/fdir-6.5.0.tgz",
@@ -1781,6 +1967,16 @@
         "yallist": "^3.0.2"
       }
     },
+    "node_modules/magic-string": {
+      "version": "0.30.21",
+      "resolved": "https://registry.npmjs.org/magic-string/-/magic-string-0.30.21.tgz",
+      "integrity": "sha512-vd2F4YUyEXKGcLHoq+TEyCjxueSeHnFxyyjNp80yg0XV4vUhnDer/lvvlqM/arB5bXQN5K2/3oinyCRyx8T2CQ==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@jridgewell/sourcemap-codec": "^1.5.5"
+      }
+    },
     "node_modules/math-intrinsics": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/math-intrinsics/-/math-intrinsics-1.1.0.tgz",
@@ -1846,6 +2042,27 @@
         "node": ">=18"
       }
     },
+    "node_modules/obug": {
+      "version": "2.1.4",
+      "resolved": "https://registry.npmjs.org/obug/-/obug-2.1.4.tgz",
+      "integrity": "sha512-4a+OsYv9UktOJKE+l1A4OufDgdRF9PifWj+tJnHURo/P+WOxpG4GzUFL9qCalmWauao6ogiG+QvnCovwPoyAWA==",
+      "dev": true,
+      "funding": [
+        "https://github.com/sponsors/sxzz",
+        "https://opencollective.com/debug"
+      ],
+      "license": "MIT",
+      "engines": {
+        "node": ">=12.20.0"
+      }
+    },
+    "node_modules/pathe": {
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/pathe/-/pathe-2.0.3.tgz",
+      "integrity": "sha512-WUjGcAqP1gQacoQe+OBJsFA7Ld4DyXuUIjZ5cc75cLHvJ7dtNsTugphxIADwspS+AraAUePCKrSVtPLFj/F88w==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/picocolors": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/picocolors/-/picocolors-1.1.1.tgz",
@@ -2040,6 +2257,13 @@
       "integrity": "sha512-oeM1lpU/UvhTxw+g3cIfxXHyJRc/uidd3yK1P242gzHds0udQBYzs3y8j4gCCW+ZJ7ad0yctld8RYO+bdurlvw==",
       "license": "MIT"
     },
+    "node_modules/siginfo": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/siginfo/-/siginfo-2.0.0.tgz",
+      "integrity": "sha512-ybx0WO1/8bSBLEWXZvEd7gMW3Sn3JFlW3TvX1nREbDLRNQNaeNN8WK0meBwPdAaOI7TtRRRJn/Es1zhrrCHu7g==",
+      "dev": true,
+      "license": "ISC"
+    },
     "node_modules/source-map-js": {
       "version": "1.2.1",
       "resolved": "https://registry.npmjs.org/source-map-js/-/source-map-js-1.2.1.tgz",
@@ -2056,6 +2280,37 @@
       "integrity": "sha512-gcj8zBWU5cFsi9WUP+4bFNXAyF1iRpA3LLyS/DP5xlrNzGmPIizUeBggKa8DbDwdqaKwUcTEnChtd2grWo/x/A==",
       "license": "MIT"
     },
+    "node_modules/stackback": {
+      "version": "0.0.2",
+      "resolved": "https://registry.npmjs.org/stackback/-/stackback-0.0.2.tgz",
+      "integrity": "sha512-1XMJE5fQo1jGH6Y/7ebnwPOBEkIEnT4QF32d5R1+VXdXveM0IBMJt8zfaxX1P3QhVwrYe+576+jkANtSS2mBbw==",
+      "dev": true,
+      "license": "MIT"
+    },
+    "node_modules/std-env": {
+      "version": "4.2.0",
+      "resolved": "https://registry.npmjs.org/std-env/-/std-env-4.2.0.tgz",
+      "integrity": "sha512-oCUKSupKTHX53EyjDtuZQ64pjLJ6yYCtpmEw0goYxtjG9KpbRe8KAsl2tBUGU9DyMcJ0RwJ8GqJAFzMXcXW1Rw==",
+      "dev": true,
+      "license": "MIT"
+    },
+    "node_modules/tinybench": {
+      "version": "2.9.0",
+      "resolved": "https://registry.npmjs.org/tinybench/-/tinybench-2.9.0.tgz",
+      "integrity": "sha512-0+DUvqWMValLmha6lr4kD8iAMK1HzV0/aKnCtWb9v9641TnP/MFb7Pc2bxoxQjTXAErryXVgUOfv2YqNllqGeg==",
+      "dev": true,
+      "license": "MIT"
+    },
+    "node_modules/tinyexec": {
+      "version": "1.2.4",
+      "resolved": "https://registry.npmjs.org/tinyexec/-/tinyexec-1.2.4.tgz",
+      "integrity": "sha512-SHf/r48b7vOrjve9PxJo3MN5v5yuyjHvdUcrQffT3WXMUfnGmHDVbC4k3sHJaJTgZCwpUplIaAo5ANtMyp3YHg==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      }
+    },
     "node_modules/tinyglobby": {
       "version": "0.2.17",
       "resolved": "https://registry.npmjs.org/tinyglobby/-/tinyglobby-0.2.17.tgz",
@@ -2073,6 +2328,16 @@
         "url": "https://github.com/sponsors/SuperchupuDev"
       }
     },
+    "node_modules/tinyrainbow": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/tinyrainbow/-/tinyrainbow-3.1.0.tgz",
+      "integrity": "sha512-Bf+ILmBgretUrdJxzXM0SgXLZ3XfiaUuOj/IKQHuTXip+05Xn+uyEYdVg0kYDipTBcLrCVyUzAPz7QmArb0mmw==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=14.0.0"
+      }
+    },
     "node_modules/update-browserslist-db": {
       "version": "1.2.3",
       "resolved": "https://registry.npmjs.org/update-browserslist-db/-/update-browserslist-db-1.2.3.tgz",
@@ -2179,6 +2444,113 @@
         }
       }
     },
+    "node_modules/vitest": {
+      "version": "4.1.10",
+      "resolved": "https://registry.npmjs.org/vitest/-/vitest-4.1.10.tgz",
+      "integrity": "sha512-R9jUTe5S4Qb0HCd4TNqpC7oGcrMssMRGXLW80ubjWsW9VH5GF8y1Y0SFLY9AbqSk6nt0PnOx4H4WNJYZ13GUPw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@vitest/expect": "4.1.10",
+        "@vitest/mocker": "4.1.10",
+        "@vitest/pretty-format": "4.1.10",
+        "@vitest/runner": "4.1.10",
+        "@vitest/snapshot": "4.1.10",
+        "@vitest/spy": "4.1.10",
+        "@vitest/utils": "4.1.10",
+        "es-module-lexer": "^2.0.0",
+        "expect-type": "^1.3.0",
+        "magic-string": "^0.30.21",
+        "obug": "^2.1.1",
+        "pathe": "^2.0.3",
+        "picomatch": "^4.0.3",
+        "std-env": "^4.0.0-rc.1",
+        "tinybench": "^2.9.0",
+        "tinyexec": "^1.0.2",
+        "tinyglobby": "^0.2.15",
+        "tinyrainbow": "^3.1.0",
+        "vite": "^6.0.0 || ^7.0.0 || ^8.0.0",
+        "why-is-node-running": "^2.3.0"
+      },
+      "bin": {
+        "vitest": "vitest.mjs"
+      },
+      "engines": {
+        "node": "^20.0.0 || ^22.0.0 || >=24.0.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      },
+      "peerDependencies": {
+        "@edge-runtime/vm": "*",
+        "@opentelemetry/api": "^1.9.0",
+        "@types/node": "^20.0.0 || ^22.0.0 || >=24.0.0",
+        "@vitest/browser-playwright": "4.1.10",
+        "@vitest/browser-preview": "4.1.10",
+        "@vitest/browser-webdriverio": "4.1.10",
+        "@vitest/coverage-istanbul": "4.1.10",
+        "@vitest/coverage-v8": "4.1.10",
+        "@vitest/ui": "4.1.10",
+        "happy-dom": "*",
+        "jsdom": "*",
+        "vite": "^6.0.0 || ^7.0.0 || ^8.0.0"
+      },
+      "peerDependenciesMeta": {
+        "@edge-runtime/vm": {
+          "optional": true
+        },
+        "@opentelemetry/api": {
+          "optional": true
+        },
+        "@types/node": {
+          "optional": true
+        },
+        "@vitest/browser-playwright": {
+          "optional": true
+        },
+        "@vitest/browser-preview": {
+          "optional": true
+        },
+        "@vitest/browser-webdriverio": {
+          "optional": true
+        },
+        "@vitest/coverage-istanbul": {
+          "optional": true
+        },
+        "@vitest/coverage-v8": {
+          "optional": true
+        },
+        "@vitest/ui": {
+          "optional": true
+        },
+        "happy-dom": {
+          "optional": true
+        },
+        "jsdom": {
+          "optional": true
+        },
+        "vite": {
+          "optional": false
+        }
+      }
+    },
+    "node_modules/why-is-node-running": {
+      "version": "2.3.0",
+      "resolved": "https://registry.npmjs.org/why-is-node-running/-/why-is-node-running-2.3.0.tgz",
+      "integrity": "sha512-hUrmaWBdVDcxvYqnyh09zunKzROWjbZTiNy8dBEjkS7ehEDQibXJ7XvlmtbwuTclUiIyN+CyXQD4Vmko8fNm8w==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "siginfo": "^2.0.0",
+        "stackback": "0.0.2"
+      },
+      "bin": {
+        "why-is-node-running": "cli.js"
+      },
+      "engines": {
+        "node": ">=8"
+      }
+    },
     "node_modules/yallist": {
       "version": "3.1.1",
       "resolved": "https://registry.npmjs.org/yallist/-/yallist-3.1.1.tgz",
diff --git a/frontend/package.json b/frontend/package.json
index c1ff77b..c0bce7b 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -6,7 +6,8 @@
   "scripts": {
     "dev": "vite",
     "build": "vite build",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "test": "vitest run"
   },
   "dependencies": {
     "axios": "^1.7.9",
@@ -17,6 +18,7 @@
   },
   "devDependencies": {
     "@vitejs/plugin-react": "^4.3.4",
-    "vite": "^6.0.7"
+    "vite": "^6.0.7",
+    "vitest": "^4.1.10"
   }
 }
diff --git a/frontend/src/lib/runSql.test.js b/frontend/src/lib/runSql.test.js
new file mode 100644
index 0000000..740938e
--- /dev/null
+++ b/frontend/src/lib/runSql.test.js
@@ -0,0 +1,79 @@
+// 이 파일이 하는 일: SQL 채점 순수함수 gradeSql의 단위 테스트다(프론트 첫 테스트).
+//
+// 학습 포인트 — 왜 하필 gradeSql부터인가?
+//   gradeSql은 학생의 SQL이 "통과/실패"인지를 결정하고, 서버는 그 판정을 그대로 믿고 저장한다.
+//   즉 이 함수가 조용히 깨지면 학생의 진도가 잘못 기록된다 — 값어치가 큰데, 순수함수라
+//   (입력만 주면 출력이 정해짐, DOM·네트워크 없음) 테스트하기도 가장 쉽다. 첫 테스트로 딱이다.
+//   (runSql·runJs는 Web Worker·WASM에 의존해 jsdom에서 어려우니 이번 범위 밖 — 후속 티켓.)
+//
+// 실행: frontend/에서  npm test   (vitest run)
+import { describe, it, expect } from 'vitest';
+import { gradeSql } from './runSql';
+
+// gradeSql(actual, expected)
+//   actual   = { columns: [...], rows: [[...], ...] }   ← 학생 쿼리 실행 결과
+//   expected = { expectedColumns, expectedRows, orderMatters }  ← 문제의 정답
+const expected = (rows, orderMatters = false) => ({ expectedRows: rows, orderMatters });
+const actual = (rows, columns = []) => ({ columns, rows });
+
+describe('gradeSql', () => {
+  it('행 개수가 다르면 오답(false)', () => {
+    const res = gradeSql(actual([[1], [2]]), expected([[1], [2], [3]]));
+    expect(res).toBe(false);
+  });
+
+  it('내용이 정확히 같으면 정답(true)', () => {
+    const rows = [['김하늘', 3200], ['이준호', 4100]];
+    expect(gradeSql(actual(rows), expected(rows, true))).toBe(true);
+  });
+
+  it('orderMatters=false: 순서가 달라도 값이 같으면 정답', () => {
+    const res = gradeSql(
+      actual([['이준호', 4100], ['김하늘', 3200]]),
+      expected([['김하늘', 3200], ['이준호', 4100]], false),
+    );
+    expect(res).toBe(true);
+  });
+
+  it('orderMatters=true: 순서가 다르면 오답 (ORDER BY 문제)', () => {
+    const res = gradeSql(
+      actual([['이준호', 4100], ['김하늘', 3200]]),
+      expected([['김하늘', 3200], ['이준호', 4100]], true),
+    );
+    expect(res).toBe(false);
+  });
+
+  it('orderMatters=true: 순서까지 같으면 정답', () => {
+    const rows = [['서지민', 4500], ['이준호', 4100], ['한지우', 3800]];
+    expect(gradeSql(actual(rows), expected(rows, true))).toBe(true);
+  });
+
+  it('컬럼명(별칭)은 채점에 영향 없음 — 값만 비교한다', () => {
+    // 학생이 SELECT salary AS 연봉 처럼 별칭을 붙여 columns가 달라도, 값이 같으면 정답.
+    const res = gradeSql(
+      actual([['김하늘', 3200]], ['name', '연봉']),      // 학생 컬럼명
+      expected([['김하늘', 3200]], false),                // 정답엔 컬럼명 비교 항목 없음
+    );
+    expect(res).toBe(true);
+  });
+
+  it('값이 하나라도 다르면 오답', () => {
+    const res = gradeSql(
+      actual([['김하늘', 3200]]),
+      expected([['김하늘', 9999]], false),
+    );
+    expect(res).toBe(false);
+  });
+
+  it('빈 결과끼리는 정답(true)', () => {
+    expect(gradeSql(actual([]), expected([], false))).toBe(true);
+  });
+
+  it('숫자와 문자열은 구분한다 (3200 ≠ "3200")', () => {
+    const res = gradeSql(
+      actual([[3200]]),
+      expected([['3200']], false),
+    );
+    expect(res).toBe(false);
+  });
+});