test: add full test coverage for notes, ues, ue-modules, ajustements, enseignements, users

- Unit tests (mock DB + API) for all missing endpoints
- Integration tests (Drizzle direct) for all missing entities
- E2E tests (handler + real DB) for all missing endpoints
- Robustness tests: invalid inputs, SQL injection, type errors, business rule violations
- Seed helpers: seedNotes, seedUeModules, seedEnseignements, seedAjustements
- Add test:coverage and test:coverage:html tasks to deno.json

Tests expose known handler bugs (marked [BUG] in test names):
- ajustements PUT/DELETE: .where() without and() modifies all rows for student
- Missing try/catch in modules, users, enseignements handlers
- Whitespace accepted as valid string values
- No type or business rule validation (note bounds, coeff >= 0)

tests/integration/ajustements_test.ts

@@ -0,0 +1,127 @@
+// Integration tests for /ajustements — Drizzle ORM direct on real DB
+
+import { assertEquals, assertExists, assertRejects } from "@std/assert";
+import {
+  seedAjustements,
+  seedPromotions,
+  seedStudents,
+  seedUes,
+  testDb,
+  truncateAll,
+} from "../helpers/db_integration.ts";
+import { ajustements } from "$root/databases/schema.ts";
+import { and, eq } from "npm:drizzle-orm@0.45.2";
+
+Deno.test({
+  name: "integration ajustements: list all ajustements",
+  async fn() {
+    await truncateAll();
+    await seedPromotions([{ id: "P1" }]);
+    const [s] = await seedStudents([{ nom: "Dupont", prenom: "Jean", idPromo: "P1" }]);
+    const [ue] = await seedUes([{ nom: "UE Info" }]);
+    await seedAjustements([{ numEtud: s.numEtud, idUE: ue.id, valeur: 13.0 }]);
+    const rows = await testDb.select().from(ajustements);
+    assertEquals(rows.length, 1);
+  },
+  sanitizeResources: false,
+  sanitizeOps: false,
+});
+
+Deno.test({
+  name: "integration ajustements: create and retrieve by composite key",
+  async fn() {
+    await truncateAll();
+    await seedPromotions([{ id: "P1" }]);
+    const [s] = await seedStudents([{ nom: "Martin", prenom: "Alice", idPromo: "P1" }]);
+    const [ue] = await seedUes([{ nom: "UE Maths" }]);
+
+    const [created] = await testDb
+      .insert(ajustements)
+      .values({ numEtud: s.numEtud, idUE: ue.id, valeur: 15.5 })
+      .returning();
+    assertExists(created);
+    assertEquals(created.valeur, 15.5);
+
+    const row = await testDb
+      .select()
+      .from(ajustements)
+      .where(and(eq(ajustements.numEtud, s.numEtud), eq(ajustements.idUE, ue.id)))
+      .then((r) => r[0] ?? null);
+    assertExists(row);
+    assertEquals(row.valeur, 15.5);
+  },
+  sanitizeResources: false,
+  sanitizeOps: false,
+});
+
+Deno.test({
+  name: "integration ajustements: get by composite key returns null when not found",
+  async fn() {
+    await truncateAll();
+    const row = await testDb
+      .select()
+      .from(ajustements)
+      .where(and(eq(ajustements.numEtud, 99999), eq(ajustements.idUE, 99)))
+      .then((r) => r[0] ?? null);
+    assertEquals(row, null);
+  },
+  sanitizeResources: false,
+  sanitizeOps: false,
+});
+
+Deno.test({
+  name: "integration ajustements: duplicate composite key insert fails",
+  async fn() {
+    await truncateAll();
+    await seedPromotions([{ id: "P1" }]);
+    const [s] = await seedStudents([{ nom: "Durand", prenom: "Claire", idPromo: "P1" }]);
+    const [ue] = await seedUes([{ nom: "UE Info" }]);
+    await seedAjustements([{ numEtud: s.numEtud, idUE: ue.id, valeur: 12.0 }]);
+    await assertRejects(() =>
+      testDb.insert(ajustements).values({ numEtud: s.numEtud, idUE: ue.id, valeur: 13.0 })
+    );
+  },
+  sanitizeResources: false,
+  sanitizeOps: false,
+});
+
+Deno.test({
+  name: "integration ajustements: update valeur",
+  async fn() {
+    await truncateAll();
+    await seedPromotions([{ id: "P1" }]);
+    const [s] = await seedStudents([{ nom: "Bernard", prenom: "Lucie", idPromo: "P1" }]);
+    const [ue] = await seedUes([{ nom: "UE Physique" }]);
+    await seedAjustements([{ numEtud: s.numEtud, idUE: ue.id, valeur: 10.0 }]);
+
+    const [updated] = await testDb
+      .update(ajustements)
+      .set({ valeur: 18.0 })
+      .where(and(eq(ajustements.numEtud, s.numEtud), eq(ajustements.idUE, ue.id)))
+      .returning();
+    assertEquals(updated.valeur, 18.0);
+  },
+  sanitizeResources: false,
+  sanitizeOps: false,
+});
+
+Deno.test({
+  name: "integration ajustements: delete removes the ajustement",
+  async fn() {
+    await truncateAll();
+    await seedPromotions([{ id: "P1" }]);
+    const [s] = await seedStudents([{ nom: "Thomas", prenom: "Eva", idPromo: "P1" }]);
+    const [ue] = await seedUes([{ nom: "UE Chimie" }]);
+    await seedAjustements([{ numEtud: s.numEtud, idUE: ue.id, valeur: 11.0 }]);
+
+    await testDb.delete(ajustements).where(and(eq(ajustements.numEtud, s.numEtud), eq(ajustements.idUE, ue.id)));
+    const row = await testDb
+      .select()
+      .from(ajustements)
+      .where(and(eq(ajustements.numEtud, s.numEtud), eq(ajustements.idUE, ue.id)))
+      .then((r) => r[0] ?? null);
+    assertEquals(row, null);
+  },
+  sanitizeResources: false,
+  sanitizeOps: false,
+});