diff --git a/tests/test_install.sh b/tests/test_install.sh
new file mode 100755
index 0000000..a433db3
--- /dev/null
+++ b/tests/test_install.sh
@@ -0,0 +1,170 @@
+#!/usr/bin/env bash
+# Tests unitaires pour install.sh
+# Usage : cd tests && bash test_install.sh
+set -euo pipefail
+
+PASS=0
+FAIL=0
+
+assert_eq() {
+    local desc="$1" expected="$2" actual="$3"
+    if [[ "$expected" == "$actual" ]]; then
+        echo "  ✓ $desc"
+        (( PASS++ )) || true
+    else
+        echo "  ✗ $desc"
+        echo "    attendu : '$expected'"
+        echo "    obtenu  : '$actual'"
+        (( FAIL++ )) || true
+    fi
+}
+
+assert_true() {
+    local desc="$1"
+    shift
+    if eval "$@" 2>/dev/null; then
+        echo "  ✓ $desc"
+        (( PASS++ )) || true
+    else
+        echo "  ✗ $desc"
+        (( FAIL++ )) || true
+    fi
+}
+
+assert_false() {
+    local desc="$1"
+    shift
+    if ! eval "$@" 2>/dev/null; then
+        echo "  ✓ $desc"
+        (( PASS++ )) || true
+    else
+        echo "  ✗ $desc"
+        (( FAIL++ )) || true
+    fi
+}
+
+# Charge install.sh sans exécuter main()
+load_install() {
+    local tmp; tmp=$(mktemp)
+    # Supprime l'appel final à main et desactive set -e pour le sourcing
+    grep -v '^main "\$@"' ../install.sh > "$tmp"
+    set +e
+    # shellcheck disable=SC1090
+    source "$tmp"
+    set -e
+    rm -f "$tmp"
+}
+
+echo ""
+echo "══════════════════════════════════"
+echo "   Tests install.sh"
+echo "══════════════════════════════════"
+echo ""
+
+load_install
+# Désactive le trap cleanup() hérité de install.sh (évite l'erreur nounset sur STATE_FILE)
+trap - EXIT
+
+# ── 1. Comparaison de versions ────────────────────────────────────
+echo "1. version_is_newer()"
+assert_true  "1.2.0 > 1.0.0"             "version_is_newer '1.0.0' '1.2.0'"
+assert_false "1.0.0 n'est pas > 1.2.0"   "version_is_newer '1.2.0' '1.0.0'"
+assert_false "1.0.0 == 1.0.0 → false"    "version_is_newer '1.0.0' '1.0.0'"
+assert_true  "2.0.0 > 1.9.9"             "version_is_newer '1.9.9' '2.0.0'"
+assert_true  "1.0.1 > 1.0.0"             "version_is_newer '1.0.0' '1.0.1'"
+
+# ── 2. Parsing frontmatter ────────────────────────────────────────
+echo ""
+echo "2. get_frontmatter_field()"
+
+TMP_SKILL=$(mktemp --suffix=.md)
+cat > "$TMP_SKILL" << 'SKILL_EOF'
+---
+name: test-skill
+version: 2.1.0
+description: Skill de test pour vérification
+agents: [claude-code]
+category: dev
+tags: [bash, test]
+---
+# Contenu du skill
+SKILL_EOF
+
+assert_eq "version"    "2.1.0"       "$(get_frontmatter_field "$TMP_SKILL" "version")"
+assert_eq "name"       "test-skill"  "$(get_frontmatter_field "$TMP_SKILL" "name")"
+assert_eq "category"   "dev"         "$(get_frontmatter_field "$TMP_SKILL" "category")"
+assert_eq "champ absent → vide" "" "$(get_frontmatter_field "$TMP_SKILL" "nonexistent")"
+rm -f "$TMP_SKILL"
+
+# ── 3. Chemins de destination ─────────────────────────────────────
+echo ""
+echo "3. get_dest_path()"
+
+assert_eq "claude global" \
+    "$HOME/.claude/skills/dev/debugging/SKILL.md" \
+    "$(get_dest_path "dev" "debugging" "claude-code" "global")"
+
+assert_eq "claude local" \
+    ".claude/skills/dev/debugging/SKILL.md" \
+    "$(get_dest_path "dev" "debugging" "claude-code" "local")"
+
+assert_eq "gemini local" \
+    ".gemini/skills/dev/debugging/SKILL.md" \
+    "$(get_dest_path "dev" "debugging" "gemini-cli" "local")"
+
+assert_eq "codex global" \
+    "$HOME/.codex/skills/jardinage/arrosage/SKILL.md" \
+    "$(get_dest_path "jardinage" "arrosage" "codex" "global")"
+
+assert_eq "hermes local" \
+    ".hermes/skills/electronique/arduino/SKILL.md" \
+    "$(get_dest_path "electronique" "arduino" "hermes" "local")"
+
+# ── 4. Gestion d'état ─────────────────────────────────────────────
+echo ""
+echo "4. state_get() / state_cycle() / make_key()"
+
+STATE_FILE=$(mktemp)
+export STATE_FILE
+
+# Teste make_key — prend une entrée "cat|skill|agent|etat|repo_ver|local_ver"
+assert_eq "make_key basique" \
+    "dev_debugging_claude_code" \
+    "$(make_key "dev|debugging|claude-code|new|1.0.0|")"
+
+assert_eq "make_key avec tirets" \
+    "dev_git_workflow_claude_code" \
+    "$(make_key "dev|git-workflow|claude-code|new|1.0.0|")"
+
+# Initialise un état
+echo "dev_debugging_claude_code=local" > "$STATE_FILE"
+
+assert_eq "state_get local" "local" "$(state_get "dev_debugging_claude_code")"
+
+state_cycle "dev_debugging_claude_code" "ok"
+assert_eq "cycle local→global" "global" "$(state_get "dev_debugging_claude_code")"
+
+state_cycle "dev_debugging_claude_code" "ok"
+assert_eq "cycle global→skip"  "skip"   "$(state_get "dev_debugging_claude_code")"
+
+state_cycle "dev_debugging_claude_code" "ok"
+assert_eq "cycle skip→local (état ok)" "local" "$(state_get "dev_debugging_claude_code")"
+
+# Teste le cycle avec état upd
+echo "dev_debugging_claude_code=skip" > "$STATE_FILE"
+state_cycle "dev_debugging_claude_code" "upd"
+assert_eq "cycle skip→update (état upd)" "update" "$(state_get "dev_debugging_claude_code")"
+
+state_cycle "dev_debugging_claude_code" "upd"
+assert_eq "cycle update→local" "local" "$(state_get "dev_debugging_claude_code")"
+
+rm -f "$STATE_FILE"
+unset STATE_FILE || true
+
+# ── Bilan ─────────────────────────────────────────────────────────
+echo ""
+echo "══════════════════════════════════"
+printf "  Résultats : %d passés, %d échoués\n" "$PASS" "$FAIL"
+echo "══════════════════════════════════"
+echo ""
+[[ "$FAIL" -eq 0 ]]