diff --git a/.githooks/pre-commit b/.githooks/pre-commit
new file mode 100755
index 0000000..f4b4092
--- /dev/null
+++ b/.githooks/pre-commit
@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+set -euo pipefail
+exec "$(git rev-parse --show-toplevel)/scripts/pre-commit.sh"
diff --git a/.github/workflows/assets/lib.sh b/.github/workflows/assets/lib.sh
index 7462c9a..10e9f23 100644
--- a/.github/workflows/assets/lib.sh
+++ b/.github/workflows/assets/lib.sh
@@ -14,6 +14,21 @@ set_git_bot_config() {
 
 repo_exists() { gh repo view "$1/$2" &>/dev/null; }
 
+# Returns 0 if org/repo has an open PR into local-{lang_code} with head matching
+# "translation-{lang_code}-*"; 1 if none; 2 if the GitHub API check failed.
+has_open_translation_pr() {
+  local org="$1" repo="$2" lang_code="$3"
+  local base_br="local-${lang_code}"
+  local output
+  if ! output=$(gh pr list --repo "$org/$repo" --state open --base "$base_br" --json headRefName \
+    --jq ".[] | select(.headRefName | startswith(\"translation-${lang_code}-\")) | .headRefName" \
+    2>&1); then
+    echo "  Error: could not list open PRs for $org/$repo (base=$base_br): $output" >&2
+    return 2
+  fi
+  [[ -n "$output" ]]
+}
+
 # ── Git clone helpers ────────────────────────────────────────────────
 
 # Clone repo at branch/tag into $3. Pass "keep" as $4 to preserve .git.
@@ -197,6 +212,22 @@ parse_list() {
   done
 }
 
+# Parse "[.adoc, .md]" or '[".adoc",".md"]' into one extension per line.
+parse_extensions() {
+  local s="$1"
+  s="${s//[[:space:]]/}"; [[ -z "$s" ]] && return
+  s="${s#[}"; s="${s%]}"
+  local result=()
+  IFS=',' read -ra parts <<< "$s"
+  for part in "${parts[@]}"; do
+    part="${part//\"/}"; part="${part//\'/}"
+    [[ -z "$part" ]] && continue
+    [[ "$part" == .* ]] || part=".${part}"
+    result+=("$part")
+  done
+  printf '%s\n' "${result[@]}"
+}
+
 # Return 0 when $1 is a well-formed Weblate language code.
 is_valid_lang_code() {
   local code="$1"
diff --git a/.github/workflows/assets/translation.sh b/.github/workflows/assets/translation.sh
new file mode 100644
index 0000000..86a2c6c
--- /dev/null
+++ b/.github/workflows/assets/translation.sh
@@ -0,0 +1,116 @@
+# shellcheck shell=bash
+# start-translation orchestration helpers.
+# Source after env.sh and lib.sh. Requires globals:
+# MODULE_ORG, MASTER_BRANCH, BOOST_ORG, BOOST_WORK, ORG_WORK, libs_ref,
+# lang_codes_arr, add_or_update (associative), ORG_REPO_MISSING, META_MISSING,
+# NO_DOC_PATHS, GITHUB_WORKSPACE.
+# shellcheck disable=SC2034,SC2154
+
+# Wipe dest_repo (except .git), copy pruned source, commit, push master only.
+sync_repo_master() {
+  local dest_repo="$1" sub_clone="$2" libs_ref="$3"
+  find "$dest_repo" -mindepth 1 -maxdepth 1 ! -name '.git' -exec rm -rf {} + || return 2
+  cp -r "$sub_clone/." "$dest_repo/" || return 2
+  set_git_bot_config "$dest_repo"
+  git -C "$dest_repo" add -A || return 2
+  if ! git -C "$dest_repo" diff --cached --quiet; then
+    git -C "$dest_repo" commit -m "Update the original documentation of $libs_ref" || return 2
+  fi
+  git -C "$dest_repo" push origin "$MASTER_BRANCH" || return 2
+}
+
+# Merge master into local-{lang_code} and push.
+update_local_merge_from_master() {
+  local repo_dir="$1" lang_code="$2"
+  local local_br="local-${lang_code}"
+  git -C "$repo_dir" fetch origin "$MASTER_BRANCH" || return 2
+  git -C "$repo_dir" fetch origin "$local_br" || return 2
+  git -C "$repo_dir" checkout -B "$local_br" "origin/$local_br" || return 2
+  git -C "$repo_dir" merge "origin/$MASTER_BRANCH" || return 2
+  git -C "$repo_dir" push origin "${local_br}:${local_br}" || return 2
+}
+
+# Create local-{lang_code} in a library mirror repo from master, with create-tag.yml.
+ensure_local_branch_in_repo() {
+  local dest_repo="$1" sub_name="$2" lang_code="$3"
+  local local_br="local-${lang_code}"
+  if git -C "$dest_repo" ls-remote --exit-code --heads origin "$local_br" &>/dev/null; then
+    echo "  Branch $local_br already exists in $sub_name." >&2
+    return 0
+  fi
+  echo "  Creating branch $local_br in $sub_name from $MASTER_BRANCH..." >&2
+  git -C "$dest_repo" fetch origin "$MASTER_BRANCH" || return 2
+  git -C "$dest_repo" checkout -B "$local_br" "origin/$MASTER_BRANCH" || return 2
+  add_create_tag_workflow "$dest_repo" || return 2
+  git -C "$dest_repo" push -u origin "$local_br" || return 2
+  echo "  Created branch $local_br." >&2
+}
+
+# Handle local-{lang_code} branch in a library mirror repo after master is synced.
+# Returns 0 if submodule should be added to add_or_update[lang_code]; 1 if skipped (open PR); 2 on git failure.
+process_local_branch() {
+  local dest_repo="$1" sub_name="$2" lang_code="$3"
+  local local_br="local-${lang_code}"
+  if git -C "$dest_repo" ls-remote --exit-code --heads origin "$local_br" &>/dev/null; then
+    has_open_translation_pr "$MODULE_ORG" "$sub_name" "$lang_code"
+    case $? in
+      0) echo "  Open translation PR found for $sub_name ($local_br), skipping." >&2; return 1 ;;
+      2) return 2 ;;
+    esac
+    update_local_merge_from_master "$dest_repo" "$lang_code" || return 2
+  else
+    ensure_local_branch_in_repo "$dest_repo" "$sub_name" "$lang_code" || return 2
+  fi
+  return 0
+}
+
+process_one_submodule() {
+  local sub_name="$1" doc_paths
+
+  if ! repo_exists "$MODULE_ORG" "$sub_name"; then
+    ORG_REPO_MISSING+=("$sub_name")
+    echo "  Error: $MODULE_ORG/$sub_name does not exist. Run add-submodules first." >&2
+    return 2
+  fi
+
+  doc_paths=$(get_doc_paths "$sub_name" "$libs_ref") || {
+    META_MISSING+=("$sub_name")
+    echo "  No libraries.json." >&2; return 2
+  }
+  [[ -z "$doc_paths" ]] && {
+    NO_DOC_PATHS+=("$sub_name")
+    echo "  No doc paths in metadata, skipping." >&2; return 1
+  }
+
+  local sub_clone="$BOOST_WORK/$sub_name"
+  clone_repo "https://github.com/${BOOST_ORG}/${sub_name}.git" \
+    "$libs_ref" "$sub_clone" || { echo "  Clone failed." >&2; return 2; }
+
+  local -a paths_arr
+  mapfile -t paths_arr <<< "$doc_paths"
+  prune_to_doc_only "$sub_clone" "${paths_arr[@]}"
+
+  local org_repo_url="https://github.com/${MODULE_ORG}/${sub_name}.git"
+  local dest_repo="$ORG_WORK/$sub_name"
+  clone_repo "$org_repo_url" "$MASTER_BRANCH" "$dest_repo" keep || {
+    echo "  clone_repo failed." >&2; return 2
+  }
+
+  sync_repo_master "$dest_repo" "$sub_clone" "$libs_ref" || return 2
+
+  local any_added=0 rc
+  for lang_code in "${lang_codes_arr[@]}"; do
+    if process_local_branch "$dest_repo" "$sub_name" "$lang_code"; then
+      if [[ -n "${add_or_update[$lang_code]:-}" ]]; then
+        add_or_update["$lang_code"]+=" $sub_name"
+      else
+        add_or_update["$lang_code"]="$sub_name"
+      fi
+      any_added=1
+    else
+      rc=$?
+      [[ $rc -eq 2 ]] && return 2
+    fi
+  done
+  [[ $any_added -eq 1 ]]
+}
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index bf2013c..8328259 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -14,22 +14,20 @@ jobs:
         with:
           persist-credentials: false
 
-      - name: ShellCheck
-        run: |
-          set -euo pipefail
-          shellcheck -x \
-            .github/workflows/assets/env.sh \
-            .github/workflows/assets/lib.sh \
-            scripts/*.sh
+      - name: ShellCheck and actionlint
+        run: scripts/lint.sh
 
-      - name: actionlint
-        run: |
-          set -euo pipefail
-          version="1.7.7"
-          tarball="actionlint_${version}_linux_amd64.tar.gz"
-          expected_sha256="023070a287cd8cccd71515fedc843f1985bf96c436b7effaecce67290e7e0757"
-          curl -fsSL -o "$tarball" \
-            "https://github.com/rhysd/actionlint/releases/download/v${version}/${tarball}"
-          echo "${expected_sha256}  ${tarball}" | sha256sum -c -
-          tar -xzf "$tarball"
-          ./actionlint -color
+  test:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+        with:
+          persist-credentials: false
+
+      - name: Install bats
+        run: sudo apt-get update && sudo apt-get install -y bats
+
+      - name: Run tests
+        run: make test
diff --git a/.github/workflows/start-translation.yml b/.github/workflows/start-translation.yml
index 8ed3558..c053650 100644
--- a/.github/workflows/start-translation.yml
+++ b/.github/workflows/start-translation.yml
@@ -113,159 +113,18 @@ jobs:
           source "$GITHUB_WORKSPACE/.github/workflows/assets/env.sh"
           # shellcheck source=assets/lib.sh
           source "$GITHUB_WORKSPACE/.github/workflows/assets/lib.sh"
+          # shellcheck source=assets/translation.sh
+          source "$GITHUB_WORKSPACE/.github/workflows/assets/translation.sh"
 
           # LIBS_REF: workflow env
           # shellcheck disable=SC2153
           libs_ref="${LIBS_REF:?}"
-          # BOOST_ORG: env.sh
-          # shellcheck disable=SC2153
-          boost_org="${BOOST_ORG:?}"
 
           ORG_WORK="$WORK_DIR/$MODULE_ORG"
           mkdir -p "$ORG_WORK"
 
-          # ── GitHub API helpers (via gh CLI) ──────────────────────────────────
-
-          # Returns 0 if org/repo has an open PR into local-{lang_code} with head matching
-          # "translation-{lang_code}-*".
-          has_open_translation_pr() {
-            local org="$1" repo="$2" lang_code="$3"
-            local base_br="local-${lang_code}"
-            gh pr list --repo "$org/$repo" --state open --base "$base_br" --json headRefName \
-              --jq ".[] | select(.headRefName | startswith(\"translation-${lang_code}-\")) | .headRefName" \
-              2>/dev/null | grep -q .
-          }
-
-          # ── Organization repo sync helpers ──────────────────────────────────────
-
-          # Wipe dest_repo (except .git), copy pruned source, commit, push master only.
-          sync_repo_master() {
-            local dest_repo="$1" sub_clone="$2" libs_ref="$3"
-            find "$dest_repo" -mindepth 1 -maxdepth 1 ! -name '.git' -exec rm -rf {} + || return 2
-            cp -r "$sub_clone/." "$dest_repo/" || return 2
-            set_git_bot_config "$dest_repo"
-            git -C "$dest_repo" add -A || return 2
-            if ! git -C "$dest_repo" diff --cached --quiet; then
-              git -C "$dest_repo" commit -m "Update the original documentation of $libs_ref" || return 2
-            fi
-            git -C "$dest_repo" push origin "$MASTER_BRANCH" || return 2
-          }
-
-          # Merge master into local-{lang_code} and push.
-          update_local_merge_from_master() {
-            local repo_dir="$1" lang_code="$2"
-            local local_br="local-${lang_code}"
-            git -C "$repo_dir" fetch origin "$MASTER_BRANCH" || return 2
-            git -C "$repo_dir" fetch origin "$local_br" || return 2
-            git -C "$repo_dir" checkout -B "$local_br" "origin/$local_br" || return 2
-            git -C "$repo_dir" merge "origin/$MASTER_BRANCH" || return 2
-            git -C "$repo_dir" push origin "${local_br}:${local_br}" || return 2
-          }
-
-          # Create local-{lang_code} in a library mirror repo from master, with create-tag.yml.
-          ensure_local_branch_in_repo() {
-            local dest_repo="$1" sub_name="$2" lang_code="$3"
-            local local_br="local-${lang_code}"
-            if git -C "$dest_repo" ls-remote --exit-code --heads origin "$local_br" &>/dev/null; then
-              echo "  Branch $local_br already exists in $sub_name." >&2
-              return 0
-            fi
-            echo "  Creating branch $local_br in $sub_name from $MASTER_BRANCH..." >&2
-            git -C "$dest_repo" fetch origin "$MASTER_BRANCH" || return 2
-            git -C "$dest_repo" checkout -B "$local_br" "origin/$MASTER_BRANCH" || return 2
-            add_create_tag_workflow "$dest_repo" || return 2
-            git -C "$dest_repo" push -u origin "$local_br" || return 2
-            echo "  Created branch $local_br." >&2
-          }
-
-          # Handle local-{lang_code} branch in a library mirror repo after master is synced.
-          # Returns 0 if submodule should be added to add_or_update[lang_code]; 1 if skipped (open PR); 2 on git failure.
-          process_local_branch() {
-            local dest_repo="$1" sub_name="$2" lang_code="$3"
-            local local_br="local-${lang_code}"
-            if git -C "$dest_repo" ls-remote --exit-code --heads origin "$local_br" &>/dev/null; then
-              if has_open_translation_pr "$MODULE_ORG" "$sub_name" "$lang_code"; then
-                echo "  Open translation PR found for $sub_name ($local_br), skipping." >&2
-                return 1
-              fi
-              update_local_merge_from_master "$dest_repo" "$lang_code" || return 2
-            else
-              ensure_local_branch_in_repo "$dest_repo" "$sub_name" "$lang_code" || return 2
-            fi
-            return 0
-          }
-
-          # ── Per-submodule processing ──────────────────────────────────────────
-
-          process_one_submodule() {
-            local sub_name="$1" doc_paths
-
-            if ! repo_exists "$MODULE_ORG" "$sub_name"; then
-              ORG_REPO_MISSING+=("$sub_name")
-              echo "  Error: $MODULE_ORG/$sub_name does not exist. Run add-submodules first." >&2
-              return 2
-            fi
-
-            doc_paths=$(get_doc_paths "$sub_name" "$libs_ref") || {
-              META_MISSING+=("$sub_name")
-              echo "  No libraries.json." >&2; return 2
-            }
-            [[ -z "$doc_paths" ]] && {
-              NO_DOC_PATHS+=("$sub_name")
-              echo "  No doc paths in metadata, skipping." >&2; return 1
-            }
-
-            local sub_clone="$BOOST_WORK/$sub_name"
-            clone_repo "https://github.com/${boost_org}/${sub_name}.git" \
-              "$libs_ref" "$sub_clone" || { echo "  Clone failed." >&2; return 2; }
-
-            local -a paths_arr
-            mapfile -t paths_arr <<< "$doc_paths"
-            prune_to_doc_only "$sub_clone" "${paths_arr[@]}"
-
-            local org_repo_url="https://github.com/${MODULE_ORG}/${sub_name}.git"
-            local dest_repo="$ORG_WORK/$sub_name"
-            clone_repo "$org_repo_url" "$MASTER_BRANCH" "$dest_repo" keep || {
-              echo "  clone_repo failed." >&2; return 2
-            }
-
-            sync_repo_master "$dest_repo" "$sub_clone" "$libs_ref" || return 2
-
-            local any_added=0
-            for lang_code in "${lang_codes_arr[@]}"; do
-              if process_local_branch "$dest_repo" "$sub_name" "$lang_code"; then
-                if [[ -n "${add_or_update[$lang_code]:-}" ]]; then
-                  add_or_update["$lang_code"]+=" $sub_name"
-                else
-                  add_or_update["$lang_code"]="$sub_name"
-                fi
-                any_added=1
-              else
-                rc=$?
-                [[ $rc -eq 2 ]] && return 2
-              fi
-            done
-            [[ $any_added -eq 1 ]]
-          }
-
           # ── Weblate helpers ───────────────────────────────────────────────────
 
-          # Parse "[.adoc, .md]" or '[".adoc",".md"]' into one extension per line.
-          parse_extensions() {
-            local s="$1"
-            s="${s//[[:space:]]/}"; [[ -z "$s" ]] && return
-            s="${s#[}"; s="${s%]}"
-            local result=()
-            IFS=',' read -ra parts <<< "$s"
-            for part in "${parts[@]}"; do
-              part="${part//\"/}"; part="${part//\'/}"
-              [[ -z "$part" ]] && continue
-              [[ "$part" == .* ]] || part=".${part}"
-              result+=("$part")
-            done
-            printf '%s\n' "${result[@]}"
-          }
-
           # POST to Weblate add-or-update (async: server returns 202 + task_id quickly).
           # Payload: {organization, add_or_update: {lang_code: [subs...]}, version, extensions}
           trigger_weblate() {
diff --git a/.gitignore b/.gitignore
index 59f888c..215caff 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,4 +8,7 @@
 data/
 
 # Local test scripts
-test/
\ No newline at end of file
+test/
+
+# Tool caches (actionlint binary downloaded by scripts/lint.sh)
+.cache/
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..6c692c2
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,8 @@
+.PHONY: lint test check
+lint:
+	scripts/lint.sh
+
+test:
+	scripts/test.sh
+
+check: lint test
diff --git a/README.md b/README.md
index e0c4014..4975e47 100644
--- a/README.md
+++ b/README.md
@@ -160,6 +160,28 @@ documented below.
 | `LANG_CODES`     | `add-submodules`, `start-translation` | Default language codes when **`client_payload.lang_codes`** is omitted (comma- or bracket-list, e.g. `zh_Hans,ja`). Must be set here or passed in the dispatch payload.                                                           |
 | `SUBMODULES_ORG` | `add-submodules`, `start-translation` | Optional. GitHub org for **`boostorg`** mirror repos (e.g. `CppDigest`). If unset, the org is the same as this repository’s owner. **`sync-translation`** relies on **`.gitmodules`** URLs already pointing at the correct hosts. |
 
+## Development
+
+Install git hooks (runs lint + tests before each commit):
+
+```bash
+scripts/install-git-hooks.sh
+```
+
+Requires **git** and **curl** for first-time setup. ShellCheck, actionlint, and bats are
+downloaded automatically into `.cache/` when not already installed (`apt install bats`
+is optional).
+
+Run checks manually:
+
+```bash
+make lint    # ShellCheck + actionlint
+make test    # bats test suite
+make check   # lint + test (same as pre-commit)
+```
+
+CI runs **`make test`** and **`scripts/lint.sh`** on every push and pull request.
+
 ## License
 
 This repository is distributed under the
diff --git a/scripts/install-git-hooks.sh b/scripts/install-git-hooks.sh
new file mode 100755
index 0000000..910fca0
--- /dev/null
+++ b/scripts/install-git-hooks.sh
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+# Point this repository at the version-controlled hooks in .githooks/.
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$ROOT"
+
+chmod +x .githooks/pre-commit scripts/lint.sh scripts/test.sh scripts/pre-commit.sh
+
+git config core.hooksPath .githooks
+echo "Installed git hooks from .githooks/ (core.hooksPath=.githooks)." >&2
+echo "Pre-commit runs: scripts/pre-commit.sh (lint + make test)." >&2
diff --git a/scripts/lint.sh b/scripts/lint.sh
new file mode 100755
index 0000000..c6307ce
--- /dev/null
+++ b/scripts/lint.sh
@@ -0,0 +1,154 @@
+#!/usr/bin/env bash
+# Run ShellCheck and actionlint (same checks as CI lint job).
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$ROOT"
+
+ensure_shellcheck() {
+  if command -v shellcheck >/dev/null 2>&1; then
+    SHELLCHECK_BIN="$(command -v shellcheck)"
+    return
+  fi
+
+  local version="v0.11.0"
+  local cache_dir="$ROOT/.cache/shellcheck"
+  local bin="$cache_dir/shellcheck"
+  mkdir -p "$cache_dir"
+
+  if [[ -x "$bin" ]]; then
+    SHELLCHECK_BIN="$bin"
+    return
+  fi
+
+  local os arch tarball url expected_sha256
+  os="$(uname -s)"
+  arch="$(uname -m)"
+  case "$os" in
+    Linux)
+      case "$arch" in
+        x86_64)
+          tarball="shellcheck-${version}.linux.x86_64.tar.xz"
+          expected_sha256="8c3be12b05d5c177a04c29e3c78ce89ac86f1595681cab149b65b97c4e227198"
+          ;;
+        aarch64|arm64)
+          tarball="shellcheck-${version}.linux.aarch64.tar.xz"
+          expected_sha256="12b331c1d2db6b9eb13cfca64306b1b157a86eb69db83023e261eaa7e7c14588"
+          ;;
+        *)
+          echo "lint: unsupported Linux architecture for shellcheck download: $arch" >&2
+          echo "lint: install shellcheck manually (e.g. apt install shellcheck)." >&2
+          exit 1
+          ;;
+      esac
+      ;;
+    Darwin)
+      case "$arch" in
+        x86_64)
+          tarball="shellcheck-${version}.darwin.x86_64.tar.xz"
+          expected_sha256="3c89db4edcab7cf1c27bff178882e0f6f27f7afdf54e859fa041fca10febe4c6"
+          ;;
+        arm64)
+          tarball="shellcheck-${version}.darwin.aarch64.tar.xz"
+          expected_sha256="56affdd8de5527894dca6dc3d7e0a99a873b0f004d7aabc30ae407d3f48b0a79"
+          ;;
+        *)
+          echo "lint: unsupported macOS architecture for shellcheck download: $arch" >&2
+          exit 1
+          ;;
+      esac
+      ;;
+    *)
+      echo "lint: shellcheck not found and auto-download unsupported on $os." >&2
+      echo "lint: install shellcheck manually (e.g. apt install shellcheck)." >&2
+      exit 1
+      ;;
+  esac
+
+  url="https://github.com/koalaman/shellcheck/releases/download/${version}/${tarball}"
+  if [[ ! -f "$cache_dir/$tarball" ]]; then
+    echo "lint: downloading shellcheck ${version}..." >&2
+    curl -fsSL -o "$cache_dir/$tarball" "$url"
+  fi
+  if [[ ! -d "$cache_dir/shellcheck-${version}" ]]; then
+    if [[ "$os" == "Linux" ]]; then
+      echo "${expected_sha256}  $cache_dir/$tarball" | sha256sum -c -
+    else
+      echo "${expected_sha256}  $cache_dir/$tarball" | shasum -a 256 -c -
+    fi
+    if ! tar -xJf "$cache_dir/$tarball" -C "$cache_dir"; then
+      echo "lint: failed to extract shellcheck (is xz installed? apt install xz-utils)." >&2
+      exit 1
+    fi
+  fi
+  cp "$cache_dir/shellcheck-${version}/shellcheck" "$bin"
+  chmod +x "$bin"
+  SHELLCHECK_BIN="$bin"
+}
+
+ensure_shellcheck
+
+"$SHELLCHECK_BIN" -x \
+  .github/workflows/assets/env.sh \
+  .github/workflows/assets/lib.sh \
+  .github/workflows/assets/translation.sh \
+  scripts/*.sh \
+  tests/helpers/*.bash
+
+ACTIONLINT_VERSION="1.7.7"
+CACHE_DIR="$ROOT/.cache/actionlint"
+ACTIONLINT_BIN="$CACHE_DIR/actionlint"
+mkdir -p "$CACHE_DIR"
+
+if [[ ! -x "$ACTIONLINT_BIN" ]]; then
+  os="$(uname -s)"
+  arch="$(uname -m)"
+  case "$os" in
+    Linux)
+      case "$arch" in
+        x86_64)
+          tarball="actionlint_${ACTIONLINT_VERSION}_linux_amd64.tar.gz"
+          expected_sha256="023070a287cd8cccd71515fedc843f1985bf96c436b7effaecce67290e7e0757"
+          ;;
+        aarch64|arm64)
+          tarball="actionlint_${ACTIONLINT_VERSION}_linux_arm64.tar.gz"
+          expected_sha256="401942f9c24ed71e4fe71b76c7d638f66d8633575c4016efd2977ce7c28317d0"
+          ;;
+        *)
+          echo "lint: unsupported Linux architecture for actionlint download: $arch" >&2
+          exit 1
+          ;;
+      esac
+      ;;
+    Darwin)
+      case "$arch" in
+        x86_64)
+          tarball="actionlint_${ACTIONLINT_VERSION}_darwin_amd64.tar.gz"
+          expected_sha256="28e5de5a05fc558474f638323d736d822fff183d2d492f0aecb2b73cc44584f5"
+          ;;
+        arm64)
+          tarball="actionlint_${ACTIONLINT_VERSION}_darwin_arm64.tar.gz"
+          expected_sha256="2693315b9093aeacb4ebd91a993fea54fc215057bf0da2659056b4bc033873db"
+          ;;
+        *)
+          echo "lint: unsupported macOS architecture for actionlint download: $arch" >&2
+          exit 1
+          ;;
+      esac
+      ;;
+    *)
+      echo "lint: unsupported OS for actionlint download: $os" >&2
+      exit 1
+      ;;
+  esac
+  curl -fsSL -o "$CACHE_DIR/$tarball" \
+    "https://github.com/rhysd/actionlint/releases/download/v${ACTIONLINT_VERSION}/${tarball}"
+  if [[ "$os" == "Linux" ]]; then
+    echo "${expected_sha256}  $CACHE_DIR/$tarball" | sha256sum -c -
+  else
+    echo "${expected_sha256}  $CACHE_DIR/$tarball" | shasum -a 256 -c -
+  fi
+  tar -xzf "$CACHE_DIR/$tarball" -C "$CACHE_DIR"
+fi
+
+"$ACTIONLINT_BIN" -color
diff --git a/scripts/pre-commit.sh b/scripts/pre-commit.sh
new file mode 100755
index 0000000..6ac355d
--- /dev/null
+++ b/scripts/pre-commit.sh
@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+# Pre-commit checks: lint (ShellCheck + actionlint) and bats tests.
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$ROOT"
+
+echo "pre-commit: running lint..." >&2
+"$ROOT/scripts/lint.sh"
+
+echo "pre-commit: running tests..." >&2
+"$ROOT/scripts/test.sh"
+
+echo "pre-commit: all checks passed." >&2
diff --git a/scripts/test.sh b/scripts/test.sh
new file mode 100755
index 0000000..acdcd68
--- /dev/null
+++ b/scripts/test.sh
@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+# Run bats tests (downloads bats-core to .cache/ if bats is not installed).
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$ROOT"
+
+ensure_bats() {
+  if command -v bats >/dev/null 2>&1; then
+    BATS_BIN="$(command -v bats)"
+    return
+  fi
+
+  local bats_commit="b640ec3cf2c7c9cfc9e6351479261186f76eeec8"
+  local cache_dir="$ROOT/.cache/bats-core"
+  local bin="$cache_dir/bin/bats"
+
+  if [[ -x "$bin" ]]; then
+    BATS_BIN="$bin"
+    return
+  fi
+
+  if ! command -v git >/dev/null 2>&1; then
+    echo "test: bats is required (e.g. apt install bats) or install git to auto-download." >&2
+    exit 1
+  fi
+
+  echo "test: downloading bats-core ${bats_commit}..." >&2
+  rm -rf "$cache_dir"
+  git init -q "$cache_dir"
+  git -C "$cache_dir" remote add origin https://github.com/bats-core/bats-core.git
+  git -C "$cache_dir" fetch --depth 1 origin "$bats_commit"
+  git -C "$cache_dir" checkout -q FETCH_HEAD
+  BATS_BIN="$bin"
+}
+
+ensure_bats
+"$BATS_BIN" tests/
diff --git a/tests/helpers/common.bash b/tests/helpers/common.bash
new file mode 100644
index 0000000..8d32cf1
--- /dev/null
+++ b/tests/helpers/common.bash
@@ -0,0 +1,61 @@
+# shellcheck shell=bash
+# Shared helpers for bats tests.
+# shellcheck disable=SC2034
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+ASSETS_DIR="$REPO_ROOT/.github/workflows/assets"
+FIXTURES_DIR="$REPO_ROOT/tests/helpers/fixtures"
+
+load_env() {
+  export GITHUB_REPOSITORY="${GITHUB_REPOSITORY:-testorg/boost-docs-translation}"
+  # shellcheck source=/dev/null
+  source "$ASSETS_DIR/env.sh"
+}
+
+load_lib() {
+  load_env
+  # shellcheck source=/dev/null
+  source "$ASSETS_DIR/lib.sh"
+}
+
+load_translation() {
+  load_lib
+  export GITHUB_WORKSPACE="$REPO_ROOT"
+  # shellcheck source=/dev/null
+  source "$ASSETS_DIR/translation.sh"
+}
+
+# Run a function and capture its exit code (works under set -e in callers).
+run_fn() {
+  local errexit_was_on=0
+  [[ $- == *e* ]] && errexit_was_on=1
+  set +e
+  "$@"
+  local rc=$?
+  if (( errexit_was_on )); then
+    set -e
+  else
+    set +e
+  fi
+  return "$rc"
+}
+
+reset_process_globals() {
+  ORG_REPO_MISSING=()
+  META_MISSING=()
+  NO_DOC_PATHS=()
+  declare -gA add_or_update=()
+  lang_codes_arr=()
+  UPDATES=()
+}
+
+init_process_globals() {
+  reset_process_globals
+  # Fixed values so tests behave the same locally and in CI (GITHUB_REPOSITORY varies).
+  MODULE_ORG="testorg"
+  MASTER_BRANCH="master"
+  BOOST_ORG="boostorg"
+  libs_ref="develop"
+  lang_codes_arr=("en")
+  add_or_update["en"]=""
+}
diff --git a/tests/helpers/fixtures/libraries-empty.json b/tests/helpers/fixtures/libraries-empty.json
new file mode 100644
index 0000000..96c9c88
--- /dev/null
+++ b/tests/helpers/fixtures/libraries-empty.json
@@ -0,0 +1,10 @@
+[
+  {
+    "name": "",
+    "key": "algorithm"
+  },
+  {
+    "name": "NoKey",
+    "key": ""
+  }
+]
diff --git a/tests/helpers/fixtures/libraries-multi.json b/tests/helpers/fixtures/libraries-multi.json
new file mode 100644
index 0000000..b2f6735
--- /dev/null
+++ b/tests/helpers/fixtures/libraries-multi.json
@@ -0,0 +1,10 @@
+[
+  {
+    "name": "Minmax",
+    "key": "minmax"
+  },
+  {
+    "name": "String",
+    "key": "string"
+  }
+]
diff --git a/tests/helpers/fixtures/libraries-single.json b/tests/helpers/fixtures/libraries-single.json
new file mode 100644
index 0000000..01144dd
--- /dev/null
+++ b/tests/helpers/fixtures/libraries-single.json
@@ -0,0 +1,6 @@
+[
+  {
+    "name": "Algorithm",
+    "key": "algorithm"
+  }
+]
diff --git a/tests/helpers/git_fixtures.bash b/tests/helpers/git_fixtures.bash
new file mode 100644
index 0000000..eb93e49
--- /dev/null
+++ b/tests/helpers/git_fixtures.bash
@@ -0,0 +1,57 @@
+# shellcheck shell=bash
+# Temp git repos for integration-style tests.
+# shellcheck disable=SC2034
+
+init_git_fixture_root() {
+  GIT_FIXTURE_ROOT="$(mktemp -d)"
+}
+
+cleanup_git_fixture_root() {
+  if [[ -n "${GIT_FIXTURE_ROOT:-}" && -d "$GIT_FIXTURE_ROOT" ]]; then
+    rm -rf "$GIT_FIXTURE_ROOT"
+  fi
+  GIT_FIXTURE_ROOT=""
+}
+
+# Create a bare remote and a working clone with an initial commit on master.
+# Sets BARE_REMOTE and WORK_REPO globals.
+create_bare_remote_with_clone() {
+  local name="$1"
+  local bare="$GIT_FIXTURE_ROOT/${name}.git"
+  local work="$GIT_FIXTURE_ROOT/${name}"
+
+  git init --bare "$bare"
+  git init "$work"
+  git -C "$work" checkout -b master
+  git -C "$work" config user.email "test@test.local"
+  git -C "$work" config user.name "Test"
+  git -C "$work" remote add origin "$bare"
+  echo "init" >"$work/README"
+  git -C "$work" add README
+  git -C "$work" commit -m "init"
+  git -C "$work" push -u origin master
+
+  BARE_REMOTE="$bare"
+  WORK_REPO="$work"
+}
+
+# Create a local branch on the bare remote (e.g. local-en).
+create_remote_branch() {
+  local bare="$1" branch="$2" from_branch="${3:-master}"
+  local tmp
+  tmp="$(mktemp -d)"
+  git clone "$bare" "$tmp"
+  git -C "$tmp" checkout -b "$branch" "origin/$from_branch"
+  git -C "$tmp" push -u origin "$branch"
+  rm -rf "$tmp"
+}
+
+# Populate a clone directory with doc-like content for prune tests.
+create_prune_fixture_dir() {
+  local dir="$1"
+  mkdir -p "$dir/doc" "$dir/src" "$dir/.github/workflows" "$dir/minmax/other"
+  echo "doc" >"$dir/doc/readme.txt"
+  echo "src" >"$dir/src/main.cpp"
+  echo "wf" >"$dir/.github/workflows/ci.yml"
+  echo "other" >"$dir/minmax/other/data.txt"
+}
diff --git a/tests/helpers/mock_gh.bash b/tests/helpers/mock_gh.bash
new file mode 100644
index 0000000..85ca83a
--- /dev/null
+++ b/tests/helpers/mock_gh.bash
@@ -0,0 +1,70 @@
+# shellcheck shell=bash
+# Install a stub gh on PATH for tests.
+
+MOCK_GH_DIR=""
+_ORIG_PATH=""
+
+install_mock_gh() {
+  _ORIG_PATH="$PATH"
+  MOCK_GH_DIR="$(mktemp -d)"
+  cat >"$MOCK_GH_DIR/gh" <<'MOCK_EOF'
+#!/usr/bin/env bash
+set -uo pipefail
+
+cmd="${1:-}"
+shift || true
+
+case "$cmd" in
+  repo)
+    if [[ "${1:-}" == "view" ]]; then
+      exit "${MOCK_REPO_VIEW_EXIT:-0}"
+    fi
+    ;;
+  api)
+    api_url="${*}"
+    if [[ "$api_url" == *libraries.json* ]]; then
+      if [[ -n "${MOCK_LIBRARIES_FIXTURE:-}" && -f "$MOCK_LIBRARIES_FIXTURE" ]]; then
+        cat "$MOCK_LIBRARIES_FIXTURE"
+      fi
+      exit "${MOCK_GH_API_EXIT:-0}"
+    fi
+    exit "${MOCK_GH_API_EXIT:-1}"
+    ;;
+  pr)
+    if [[ "${1:-}" == "list" ]]; then
+      if [[ -n "${MOCK_PR_LIST_STDERR:-}" ]]; then
+        printf '%s\n' "$MOCK_PR_LIST_STDERR" >&2
+      fi
+      if [[ -n "${MOCK_PR_LIST_STDOUT:-}" ]]; then
+        printf '%s\n' "$MOCK_PR_LIST_STDOUT"
+      fi
+      exit "${MOCK_PR_LIST_EXIT:-0}"
+    fi
+    ;;
+esac
+
+echo "mock gh: unhandled invocation: gh $*" >&2
+exit 127
+MOCK_EOF
+  chmod +x "$MOCK_GH_DIR/gh"
+  export PATH="$MOCK_GH_DIR:$PATH"
+}
+
+restore_mock_gh() {
+  if [[ -n "$_ORIG_PATH" ]]; then
+    export PATH="$_ORIG_PATH"
+  fi
+  if [[ -n "$MOCK_GH_DIR" && -d "$MOCK_GH_DIR" ]]; then
+    rm -rf "$MOCK_GH_DIR"
+  fi
+  unset MOCK_GH_DIR _ORIG_PATH
+  unset MOCK_REPO_VIEW_EXIT MOCK_LIBRARIES_FIXTURE MOCK_GH_API_EXIT
+  unset MOCK_PR_LIST_STDOUT MOCK_PR_LIST_STDERR MOCK_PR_LIST_EXIT
+}
+
+reset_mock_gh() {
+  export MOCK_REPO_VIEW_EXIT=0
+  unset MOCK_LIBRARIES_FIXTURE MOCK_GH_API_EXIT
+  unset MOCK_PR_LIST_STDOUT MOCK_PR_LIST_STDERR MOCK_PR_LIST_EXIT
+  export MOCK_PR_LIST_EXIT=0
+}
diff --git a/tests/test_lib.bats b/tests/test_lib.bats
new file mode 100644
index 0000000..f0d7de4
--- /dev/null
+++ b/tests/test_lib.bats
@@ -0,0 +1,141 @@
+#!/usr/bin/env bats
+
+setup() {
+  # shellcheck source=tests/helpers/common.bash
+  source "$BATS_TEST_DIRNAME/helpers/common.bash"
+  load_lib
+}
+
+@test "parse_list: empty input produces no output" {
+  run parse_list ""
+  [ "$status" -eq 0 ]
+  [ -z "$output" ]
+}
+
+@test "parse_list: comma-separated codes" {
+  run parse_list "zh_Hans,en"
+  [ "$status" -eq 0 ]
+  [ "$output" = $'zh_Hans\nen' ]
+}
+
+@test "parse_list: bracketed list with spaces" {
+  run parse_list "[zh_Hans, en]"
+  [ "$status" -eq 0 ]
+  [ "$output" = $'zh_Hans\nen' ]
+}
+
+@test "parse_list: trailing comma ignored" {
+  run parse_list "en,"
+  [ "$status" -eq 0 ]
+  [ "$output" = "en" ]
+}
+
+@test "parse_extensions: bracketed extensions" {
+  run parse_extensions "[.adoc, .md]"
+  [ "$status" -eq 0 ]
+  [ "$output" = $'.adoc\n.md' ]
+}
+
+@test "parse_extensions: JSON-style quoted extensions" {
+  run parse_extensions '[".adoc",".md"]'
+  [ "$status" -eq 0 ]
+  [ "$output" = $'.adoc\n.md' ]
+}
+
+@test "parse_extensions: bare extension gets dot prefix" {
+  run parse_extensions "adoc"
+  [ "$status" -eq 0 ]
+  [ "$output" = ".adoc" ]
+}
+
+@test "parse_extensions: empty input produces no output" {
+  run parse_extensions ""
+  [ "$status" -eq 0 ]
+  [ -z "$output" ]
+}
+
+@test "is_valid_lang_code: accepts common BCP 47 codes" {
+  is_valid_lang_code "en"
+  is_valid_lang_code "zh_Hans"
+  is_valid_lang_code "pt_BR"
+}
+
+@test "is_valid_lang_code: rejects invalid codes" {
+  ! is_valid_lang_code ""
+  ! is_valid_lang_code "en US"
+  ! is_valid_lang_code "zh/Hans"
+  ! is_valid_lang_code "a"
+}
+
+@test "get_doc_paths: single-library repo emits doc" {
+  # shellcheck source=tests/helpers/mock_gh.bash
+  source "$BATS_TEST_DIRNAME/helpers/mock_gh.bash"
+  install_mock_gh
+  export MOCK_LIBRARIES_FIXTURE="$FIXTURES_DIR/libraries-single.json"
+
+  run get_doc_paths "algorithm" "develop"
+  [ "$status" -eq 0 ]
+  [ "$output" = "doc" ]
+
+  restore_mock_gh
+}
+
+@test "get_doc_paths: multi-library repo emits per-key doc paths" {
+  # shellcheck source=tests/helpers/mock_gh.bash
+  source "$BATS_TEST_DIRNAME/helpers/mock_gh.bash"
+  install_mock_gh
+  export MOCK_LIBRARIES_FIXTURE="$FIXTURES_DIR/libraries-multi.json"
+
+  run get_doc_paths "container" "develop"
+  [ "$status" -eq 0 ]
+  [ "$output" = $'minmax/doc\nstring/doc' ]
+
+  restore_mock_gh
+}
+
+@test "get_doc_paths: API failure returns non-zero" {
+  # shellcheck source=tests/helpers/mock_gh.bash
+  source "$BATS_TEST_DIRNAME/helpers/mock_gh.bash"
+  install_mock_gh
+  export MOCK_GH_API_EXIT=1
+
+  run get_doc_paths "algorithm" "develop"
+  [ "$status" -eq 1 ]
+
+  restore_mock_gh
+}
+
+@test "prune_to_doc_only: keeps doc and root files, removes other dirs" {
+  # shellcheck source=tests/helpers/git_fixtures.bash
+  source "$BATS_TEST_DIRNAME/helpers/git_fixtures.bash"
+  init_git_fixture_root
+  local_dir="$GIT_FIXTURE_ROOT/prune-single"
+  create_prune_fixture_dir "$local_dir"
+  echo "root" >"$local_dir/LICENSE"
+
+  prune_to_doc_only "$local_dir" "doc"
+
+  [ -d "$local_dir/doc" ]
+  [ -f "$local_dir/LICENSE" ]
+  [ ! -d "$local_dir/src" ]
+  [ ! -d "$local_dir/.github" ]
+
+  cleanup_git_fixture_root
+}
+
+@test "prune_to_doc_only: multi-level path prunes intermediate dirs" {
+  # shellcheck source=tests/helpers/git_fixtures.bash
+  source "$BATS_TEST_DIRNAME/helpers/git_fixtures.bash"
+  init_git_fixture_root
+  local_dir="$GIT_FIXTURE_ROOT/prune-multi"
+  create_prune_fixture_dir "$local_dir"
+
+  prune_to_doc_only "$local_dir" "minmax/doc"
+
+  [ -d "$local_dir/minmax" ]
+  [ ! -d "$local_dir/minmax/other" ]
+  [ ! -d "$local_dir/doc" ]
+  [ ! -d "$local_dir/src" ]
+
+  cleanup_git_fixture_root
+}
diff --git a/tests/test_merge_guard.bats b/tests/test_merge_guard.bats
new file mode 100644
index 0000000..ada2cb0
--- /dev/null
+++ b/tests/test_merge_guard.bats
@@ -0,0 +1,81 @@
+#!/usr/bin/env bats
+
+setup() {
+  # shellcheck source=tests/helpers/common.bash
+  source "$BATS_TEST_DIRNAME/helpers/common.bash"
+  # shellcheck source=tests/helpers/mock_gh.bash
+  source "$BATS_TEST_DIRNAME/helpers/mock_gh.bash"
+  load_lib
+  install_mock_gh
+  reset_mock_gh
+}
+
+teardown() {
+  restore_mock_gh
+}
+
+@test "has_open_translation_pr: returns true when open PR exists" {
+  export MOCK_PR_LIST_STDOUT="translation-zh_Hans-foo"
+
+  run has_open_translation_pr "testorg" "algorithm" "zh_Hans"
+  [ "$status" -eq 0 ]
+}
+
+@test "has_open_translation_pr: returns false when no open PR" {
+  unset MOCK_PR_LIST_STDOUT
+
+  run has_open_translation_pr "testorg" "algorithm" "zh_Hans"
+  [ "$status" -eq 1 ]
+}
+
+@test "has_open_translation_pr: API failure returns 2 (fail-closed)" {
+  export MOCK_PR_LIST_EXIT=1
+  export MOCK_PR_LIST_STDERR="API rate limit exceeded"
+  unset MOCK_PR_LIST_STDOUT
+
+  run has_open_translation_pr "testorg" "algorithm" "zh_Hans"
+  [ "$status" -eq 2 ]
+  [[ "$output" == *"API rate limit exceeded"* ]]
+}
+
+@test "process_local_branch: returns 1 when open translation PR exists" {
+  # shellcheck source=tests/helpers/git_fixtures.bash
+  source "$BATS_TEST_DIRNAME/helpers/git_fixtures.bash"
+  load_translation
+  init_git_fixture_root
+  init_process_globals
+
+  create_bare_remote_with_clone "mirror"
+  create_remote_branch "$BARE_REMOTE" "local-en" "master"
+  dest_repo="$GIT_FIXTURE_ROOT/mirror-clone"
+  git clone "$BARE_REMOTE" "$dest_repo"
+
+  export MOCK_PR_LIST_STDOUT="translation-en-abc123"
+
+  run process_local_branch "$dest_repo" "algorithm" "en"
+  [ "$status" -eq 1 ]
+
+  cleanup_git_fixture_root
+}
+
+@test "process_local_branch: returns 2 when PR check fails" {
+  # shellcheck source=tests/helpers/git_fixtures.bash
+  source "$BATS_TEST_DIRNAME/helpers/git_fixtures.bash"
+  load_translation
+  init_git_fixture_root
+  init_process_globals
+
+  create_bare_remote_with_clone "mirror"
+  create_remote_branch "$BARE_REMOTE" "local-en" "master"
+  dest_repo="$GIT_FIXTURE_ROOT/mirror-clone"
+  git clone "$BARE_REMOTE" "$dest_repo"
+
+  export MOCK_PR_LIST_EXIT=1
+  export MOCK_PR_LIST_STDERR="API rate limit exceeded"
+  unset MOCK_PR_LIST_STDOUT
+
+  run process_local_branch "$dest_repo" "algorithm" "en"
+  [ "$status" -eq 2 ]
+
+  cleanup_git_fixture_root
+}
diff --git a/tests/test_process_submodule.bats b/tests/test_process_submodule.bats
new file mode 100644
index 0000000..fc9fb95
--- /dev/null
+++ b/tests/test_process_submodule.bats
@@ -0,0 +1,88 @@
+#!/usr/bin/env bats
+
+setup() {
+  # shellcheck source=tests/helpers/common.bash
+  source "$BATS_TEST_DIRNAME/helpers/common.bash"
+  # shellcheck source=tests/helpers/mock_gh.bash
+  source "$BATS_TEST_DIRNAME/helpers/mock_gh.bash"
+  # shellcheck source=tests/helpers/git_fixtures.bash
+  source "$BATS_TEST_DIRNAME/helpers/git_fixtures.bash"
+  load_translation
+  install_mock_gh
+  reset_mock_gh
+  init_git_fixture_root
+  init_process_globals
+
+  WORK_DIR="$(mktemp -d)"
+  BOOST_WORK="$WORK_DIR/boost"
+  ORG_WORK="$WORK_DIR/$MODULE_ORG"
+  mkdir -p "$BOOST_WORK" "$ORG_WORK"
+}
+
+teardown() {
+  restore_mock_gh
+  cleanup_git_fixture_root
+  rm -rf "${WORK_DIR:-}"
+}
+
+@test "process_one_submodule: returns 2 when mirror repo missing" {
+  export MOCK_REPO_VIEW_EXIT=1
+
+  set +e
+  process_one_submodule "missing-lib"
+  status=$?
+  set -e
+
+  [ "$status" -eq 2 ]
+  [[ " ${ORG_REPO_MISSING[*]} " == *" missing-lib "* ]]
+}
+
+@test "process_one_submodule: returns 1 when metadata has no doc paths" {
+  export MOCK_LIBRARIES_FIXTURE="$FIXTURES_DIR/libraries-empty.json"
+
+  set +e
+  process_one_submodule "algorithm"
+  status=$?
+  set -e
+
+  [ "$status" -eq 1 ]
+  [[ " ${NO_DOC_PATHS[*]} " == *" algorithm "* ]]
+}
+
+@test "process_one_submodule: returns 0 on success path" {
+  libs_ref="master"
+  export MOCK_LIBRARIES_FIXTURE="$FIXTURES_DIR/libraries-single.json"
+
+  create_bare_remote_with_clone "boost-algorithm"
+  boost_bare="$BARE_REMOTE"
+  boost_work="$WORK_REPO"
+  mkdir -p "$boost_work/doc"
+  echo "doc content" >"$boost_work/doc/page.adoc"
+  git -C "$boost_work" add doc/
+  git -C "$boost_work" commit -m "add doc"
+  git -C "$boost_work" push origin master
+
+  create_bare_remote_with_clone "mirror-algorithm"
+  mirror_bare="$BARE_REMOTE"
+
+  clone_repo() {
+    local url="$1" branch="$2" dest="$3" keep="${4:-}"
+    local bare=""
+    case "$url" in
+      *"${BOOST_ORG}/algorithm"*) bare="$boost_bare" ;;
+      *"${MODULE_ORG}/algorithm"*) bare="$mirror_bare" ;;
+      *) echo "unexpected clone url: $url (MODULE_ORG=$MODULE_ORG)" >&2; return 1 ;;
+    esac
+    mkdir -p "$dest"
+    git clone --branch "$branch" "$bare" "$dest"
+    [[ "$keep" == "keep" ]] || rm -rf "$dest/.git"
+  }
+
+  set +e
+  process_one_submodule "algorithm"
+  status=$?
+  set -e
+
+  [ "$status" -eq 0 ]
+  [[ "${add_or_update[en]}" == *algorithm* ]]
+}