Complete automated testing

tests/analyze.bats

@@ -0,0 +1,71 @@
+#!/usr/bin/env bats
+
+setup_file() {
+  PROJECT_ROOT="$(cd "${BATS_TEST_DIRNAME}/.." && pwd)"
+  export PROJECT_ROOT
+
+  ORIGINAL_HOME="${HOME:-}"
+  export ORIGINAL_HOME
+
+  HOME="$(mktemp -d "${BATS_TEST_DIRNAME}/tmp-analyze-home.XXXXXX")"
+  export HOME
+}
+
+teardown_file() {
+  rm -rf "$HOME"
+  if [[ -n "${ORIGINAL_HOME:-}" ]]; then
+    export HOME="$ORIGINAL_HOME"
+  fi
+}
+
+setup() {
+  export TERM="dumb"
+  rm -rf "${HOME:?}"/*
+  mkdir -p "$HOME"
+}
+
+@test "scan_directories lists largest folders first" {
+  run env HOME="$HOME" PROJECT_ROOT="$PROJECT_ROOT" bash --noprofile --norc <<'EOF'
+set -euo pipefail
+source "$PROJECT_ROOT/bin/analyze.sh"
+
+root="$HOME/analyze-root"
+mkdir -p "$root/Small" "$root/Large"
+printf 'tiny' > "$root/Small/file.txt"
+dd if=/dev/zero of="$root/Large/big.dat" bs=1024 count=200 >/dev/null 2>&1
+
+output_file="$HOME/directories.txt"
+scan_directories "$root" "$output_file" 1
+
+head -n1 "$output_file"
+EOF
+
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"Large"* ]]
+}
+
+@test "aggregate_by_directory sums child sizes per parent" {
+  run env HOME="$HOME" PROJECT_ROOT="$PROJECT_ROOT" bash --noprofile --norc <<'EOF'
+set -euo pipefail
+source "$PROJECT_ROOT/bin/analyze.sh"
+
+root="$HOME/group"
+mkdir -p "$root/a" "$root/b"
+
+input_file="$HOME/files.txt"
+cat > "$input_file" <<LIST
+1024|$root/a/file1
+2048|$root/a/file2
+512|$root/b/data.bin
+LIST
+
+output_file="$HOME/aggregated.txt"
+aggregate_by_directory "$input_file" "$output_file"
+
+cat "$output_file"
+EOF
+
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"3072|$HOME/group/a/"* ]]
+  [[ "$output" == *"512|$HOME/group/b/"* ]]
+}