Test Impact

Find minimal tests affected by function/module change via Codemap static analysis; run no tests. Return ready pytest command for impacted tests only.

Two input modes:

• Function-level (module::symbol) — reverse-call-graph BFS; all direct/transitive test callers + symbol mocks (mock_patches).
• Module-level (bare module) — reverse-import-graph BFS; all tests importing through any chain + any module-symbol mocks.

not_covered: dynamic dispatch, hook callbacks, string-dispatch callers; same blind spot as fn-blast. Surface caveat; log gap.

NOT for: finding all callers of a function (use /codemap-py:query-code fn-rdeps <module::symbol> --exclude-tests); querying module deps or blast radius (use /codemap-py:query-code); running/executing tests (identified here, not executed).

• $ARGUMENTS: <qname> [--no-mocks]
  • qname — module::symbol (function-level) or bare dotted module (module-level)
  • --no-mocks — exclude mock-only test files (no call/import path)
  • Omitted → AskUserQuestion in Step 1

Step 0 — Ensure index

# timeout: 10000
export CSID="${CLAUDE_CODE_SESSION_ID:-$PPID}"
_CM_PROJ=$(git rev-parse --show-toplevel 2>/dev/null | xargs basename 2>/dev/null || basename "$PWD")
_IDX="${CODEMAP_INDEX_DIR:-.cache/codemap}"
INDEX="${_IDX}/${_CM_PROJ}.json"

# dispatcher, not the scan-query/scan-index aliases — aliases lease in-engine too, but skip the dispatcher's interpreter probe (exit 127) and are deprecated shims, removed no earlier than 1.0.0
# PATH-literal invocation everywhere below — expansion-bearing form matches no bare-name allow prefix; the plugin's absolute bin/codemap-py stays the interactive fallback
command -v codemap-py >/dev/null 2>&1 || { echo "codemap-py not on PATH — install the codemap-py plugin, or invoke its bin/codemap-py launcher as one standalone command"; exit 1; }

[ ! -f "$INDEX" ] && echo "No index found — will build via codemap-py index"

SCAN_NO_AUTOBUILD=1 opts out: use index unchanged; no refresh/full build. Echo build wall-time when run, separating build/query cost.

If $INDEX missing:

• With SCAN_NO_AUTOBUILD=1: print ! codemap index missing and SCAN_NO_AUTOBUILD=1 — refusing to auto-build. Build it manually first: /codemap-py:scan-codebase; exit 1.
• Otherwise run foreground codemap-py index; wait, then continue. Never invoke codemap-py:scan-codebase: disable-model-invocation:true, user-slash-only. Build through gated codemap-py index dispatcher.

If index already exists:

# timeout: 30000
_CM_PROJ=$(git rev-parse --show-toplevel 2>/dev/null | xargs basename 2>/dev/null || basename "$PWD")
_IDX="${CODEMAP_INDEX_DIR:-.cache/codemap}"
if [ "${SCAN_NO_AUTOBUILD:-0}" = "1" ]; then
    echo "[codemap] SCAN_NO_AUTOBUILD=1 — using existing index as-is (no refresh)"
else
    _CM_BUILD_T0=$(date +%s)
    # export, not an inline env prefix — a prefix puts an expansion ahead of the binary, so the command no longer matches a bare-name allow prefix
    export CODEMAP_INDEX_DIR="${_IDX}"   # forward to the build; ensures it writes to same path as INDEX
    codemap-py index --incremental \
        && echo "[codemap] index built in $(( $(date +%s) - _CM_BUILD_T0 ))s" \
        || printf "⚠ codemap-py index --incremental failed — index may be stale; continuing\n"
fi

After build/refresh, re-verify index:

# timeout: 5000
_CM_PROJ=$(git rev-parse --show-toplevel 2>/dev/null | xargs basename 2>/dev/null || basename "$PWD")
_IDX="${CODEMAP_INDEX_DIR:-.cache/codemap}"
INDEX="${_IDX}/${_CM_PROJ}.json"
[ -f "$INDEX" ] || { printf "! Index not found after refresh at %s — check CODEMAP_INDEX_DIR or re-run /codemap-py:scan-codebase\n" "$INDEX"; exit 1; }

Step 1 — Parse arguments

Extract QNAME + NO_MOCKS from $ARGUMENTS.

# timeout: 5000
export CSID="${CLAUDE_CODE_SESSION_ID:-$PPID}"
_CM_PROJ=$(git rev-parse --show-toplevel 2>/dev/null | xargs basename 2>/dev/null || basename "$PWD")
ARGS="${ARGUMENTS:-}"
QNAME=$(echo "$ARGS" | awk '{print $1}')
MOCKS_FLAG=$(echo "$ARGS" | grep -q -- "--no-mocks" && echo "--no-mocks" || echo "")
echo "$QNAME" > "${TMPDIR:-/tmp}/codemap-${_CM_PROJ}-ti-qname-${CSID}"
echo "$MOCKS_FLAG" > "${TMPDIR:-/tmp}/codemap-${_CM_PROJ}-ti-mocks-${CSID}"

If $ARGUMENTS empty, use AskUserQuestion: "Which function or module changed?" Options: (a) Enter module::symbol for function-level; (b) Enter bare module for module-level; (c) Cancel, exit without analysis. After answer, set QNAME; write tmpfile before Step 2:

# timeout: 5000
export CSID="${CLAUDE_CODE_SESSION_ID:-$PPID}"
_CM_PROJ=$(git rev-parse --show-toplevel 2>/dev/null | xargs basename 2>/dev/null || basename "$PWD")
QNAME="<answer from AskUserQuestion>"
echo "$QNAME" > "${TMPDIR:-/tmp}/codemap-${_CM_PROJ}-ti-qname-${CSID}"

Multi-symbol guard: $ARGUMENTS may contain multiple tokens (for example mypackage.auth::validate mypackage.auth::parse); awk '{print $1}' silently keeps first. If more than one after removing --no-mocks, print ⚠ test-impact accepts one symbol at a time — using first token only: $QNAME. Run separately for each remaining symbol.

Step 2 — Run test-impact query

# timeout: 10000
export CSID="${CLAUDE_CODE_SESSION_ID:-$PPID}"
_CM_PROJ=$(git rev-parse --show-toplevel 2>/dev/null | xargs basename 2>/dev/null || basename "$PWD")
IFS= read -r QNAME < "${TMPDIR:-/tmp}/codemap-${_CM_PROJ}-ti-qname-${CSID}" 2>/dev/null || QNAME=""
IFS= read -r MOCKS_FLAG < "${TMPDIR:-/tmp}/codemap-${_CM_PROJ}-ti-mocks-${CSID}" 2>/dev/null || MOCKS_FLAG=""
_TI_ERR="${TMPDIR:-/tmp}/codemap-${_CM_PROJ}-ti-stderr-${CSID}"
# capture stderr to a file, never 2>/dev/null — a swallowed diagnostic is what rendered a broken index as "no affected tests"
RESULT=$(codemap-py query test-impact "$QNAME" $MOCKS_FLAG 2>"$_TI_ERR")
_TI_RC=$?
if [ "$_TI_RC" -ne 0 ]; then
    printf "! test-impact query failed (exit %d) — this is NOT a 'no affected tests' result; do not report an empty test set\n" "$_TI_RC" >&2
    [ -s "$_TI_ERR" ] && sed -n '1,5p' "$_TI_ERR" >&2
    printf "Rebuild with /codemap-py:scan-codebase, then re-run.\n" >&2
    exit 1
fi
# one parse, no per-field `|| echo` defaults — a default here forges total=0 out of an unparsable payload
printf '%s' "$RESULT" | python3 -c "
import json, sys
base, suf = sys.argv[1], sys.argv[2]
try:
    payload = json.loads(sys.stdin.read())
except ValueError:
    sys.stderr.write('! test-impact returned non-JSON output — NOT an empty result; rebuild via /codemap-py:scan-codebase and re-run\n')
    raise SystemExit(1)
index = payload.get('index') or {}
fields = {
    'not-covered': json.dumps(index.get('not_covered') or []),
    'hint': index.get('hint') or '',
    'total': str(len(payload.get('test_files') or [])),
    'pytest-cmd': payload.get('pytest_cmd') or '',
}
for name, value in fields.items():
    with open(base + name + suf, 'w') as handle:
        handle.write(value + '\n')
" "${TMPDIR:-/tmp}/codemap-${_CM_PROJ}-ti-" "-${CSID}" || exit 1

Parse $RESULT JSON:

• test_files — list of test file paths
• pytest_cmd — ready-to-run command
• via_call / via_mock — breakdown of how tests were found
• index.not_covered — surface as caveat if non-empty
• index.hint — include as suggestion

Loud-failure contract: query failure ≠ empty result. Shell enforces it: nonzero exits skill 1 before field reads; unparsable payload exits parser 1. Neither may become "no affected tests". False empty set from broken index is worst possible output.

haiku JSON guard: output may include log/warning prefix/suffix. Always pipe stdin into python3 -c "import json, sys; ..."; never assume raw valid JSON. Never add per-field || echo "0" / || echo "[]": failed parse must not manufacture benign defaults.

Step 3 — Output

When total == 0: reachable only after Step 2 exit 0 + parsed payload: genuine empty. Report "No tests found via static analysis. Try full suite or check with grep -rn <symbol_name> tests/."

When total > 0:

## Test impact: <qname>

**Affected tests** (<total> files, <via_call> via call/import graph, <via_mock> via mocks):
<test_files as bullet list>

**Run:**
```
<pytest_cmd>
```

<if not_covered non-empty>
**Caveat:** dynamic-dispatch / hook-callback callers are not in the static graph — <hint>.
</if>

Output routing: if total >= 5, derive free non-colliding path; write report there:

# timeout: 3000
BRANCH=$(git branch --show-current 2>/dev/null | tr '/' '-'); BRANCH="${BRANCH:-main}"
# never overwrite — a same-day re-run on another target would replace an unrelated report
TI_OUT=".temp/output-test-impact-${BRANCH}-$(date +%Y-%m-%d).md"; _n=1
while [ -e "$TI_OUT" ]; do _n=$((_n+1)); TI_OUT=".temp/output-test-impact-${BRANCH}-$(date +%Y-%m-%d)-${_n}.md"; done
printf '%s\n' "$TI_OUT"