refactor: Consolidate and refactor test suite by removing redundant files and simplifying test execution.

tests/update_manager.bats

@@ -4,6 +4,9 @@ setup_file() {
     PROJECT_ROOT="$(cd "${BATS_TEST_DIRNAME}/.." && pwd)"
     export PROJECT_ROOT
 
+    CURRENT_VERSION="$(grep '^VERSION=' "$PROJECT_ROOT/mole" | head -1 | sed 's/VERSION=\"\\(.*\\)\"/\\1/')"
+    export CURRENT_VERSION
+
     ORIGINAL_HOME="${HOME:-}"
     export ORIGINAL_HOME
 
@@ -161,3 +164,72 @@ EOF
     [[ "$output" == *"MOLE_CACHE_RESET"* ]]
     [[ "$output" == *"All updates completed"* ]]
 }
+
+@test "update_via_homebrew reports already on latest version" {
+    run env HOME="$HOME" PROJECT_ROOT="$PROJECT_ROOT" bash --noprofile --norc << 'EOF'
+set -euo pipefail
+MOLE_TEST_BREW_UPDATE_OUTPUT="Updated 0 formulae"
+MOLE_TEST_BREW_UPGRADE_OUTPUT="Warning: mole 1.7.9 already installed"
+MOLE_TEST_BREW_LIST_OUTPUT="mole 1.7.9"
+start_inline_spinner() { :; }
+stop_inline_spinner() { :; }
+brew() {
+  case "$1" in
+    update) echo "$MOLE_TEST_BREW_UPDATE_OUTPUT";;
+    upgrade) echo "$MOLE_TEST_BREW_UPGRADE_OUTPUT";;
+    list) if [[ "$2" == "--versions" ]]; then echo "$MOLE_TEST_BREW_LIST_OUTPUT"; fi ;;
+  esac
+}
+export -f brew start_inline_spinner stop_inline_spinner
+source "$PROJECT_ROOT/lib/core/common.sh"
+update_via_homebrew "1.7.9"
+EOF
+
+    [ "$status" -eq 0 ]
+    [[ "$output" == *"Already on latest version"* ]]
+}
+
+@test "update_mole skips download when already latest" {
+    run env HOME="$HOME" PROJECT_ROOT="$PROJECT_ROOT" CURRENT_VERSION="$CURRENT_VERSION" PATH="$HOME/fake-bin:/usr/bin:/bin" TERM="dumb" bash --noprofile --norc << 'EOF'
+set -euo pipefail
+curl() {
+  local out=""
+  local url=""
+  while [[ $# -gt 0 ]]; do
+    case "$1" in
+      -o)
+        out="$2"
+        shift 2
+        ;;
+      http*://*)
+        url="$1"
+        shift
+        ;;
+      *)
+        shift
+        ;;
+    esac
+  done
+
+  if [[ -n "$out" ]]; then
+    echo "Installer executed" > "$out"
+    return 0
+  fi
+
+  if [[ "$url" == *"api.github.com"* ]]; then
+    echo "{\"tag_name\":\"$CURRENT_VERSION\"}"
+  else
+    echo "VERSION=\"$CURRENT_VERSION\""
+  fi
+}
+export -f curl
+
+brew() { exit 1; }
+export -f brew
+
+"$PROJECT_ROOT/mole" update
+EOF
+
+    [ "$status" -eq 0 ]
+    [[ "$output" == *"Already on latest version"* ]]
+}