Bash Test Rigs: Assignment Chains Need Explicit Newlines

Consider this pattern:

RAW=$(curl -sf "$URL/mcp" -X POST \
  -H "Content-Type: application/json" \
  -d '...')RESULT=$(extract_json "$RAW")

The intent is two statements on two lines. The bug is the dropped newline between ) and RESULT=. Bash parses this as a single command-substitution statement assigning to RAW, with the literal characters RESULT=$(extract_json "$RAW") becoming part of RAW's right-hand side. The actual RESULT variable is never assigned — it inherits whatever value the prior test set, or remains empty.

No syntax error. No runtime error. Just a silently wrong test that asserts against last-test-leftover state.

The bash -n syntax check passes — the construct is valid bash. Detection requires either (a) reading the script with attention to line boundaries after every closing ) of a command substitution, or (b) running shellcheck (which catches some related cases but not all).

The cheapest preventive: between any two assignments in a test, leave a blank line. Visual whitespace as discipline. The bash -n check still passes; the pattern is now legible to humans.

Any shell-script test rig in this codebase, especially tests/cloudflare-production.test.sh. The pattern is most dangerous in tests that are structured as repeated RAW=$(curl); RESULT=$(extract_json "$RAW"); INNER=$(echo "$RESULT" | python3 -c ...) sequences — exactly the structure of all the smoke tests for new MCP actions.

Surfaced in klappy/oddkit#140 (PR-2.1 of the link-rot-elimination campaign). When test 14g.2 (supersession-walk smoke) was added, the boundary between its closing ) and test 14h's RESULT=$(...) lost a newline during an str_replace operation. The RAW variable for test 14h was never set; test 14h's assertion ran against the response from test 14g.2, which happened to be a FOUND response. Test 14h asserts NOT_FOUND, so it failed — but the failure message showed the URI from test 14g.2, which was confusing to debug because the reported URI was not the URI the test was supposedly calling.

Detection cost: the failure was caught by post-merge CI on klappy/oddkit#140 because preview testing exercised it. The fix was a one-character newline insertion, but the diagnostic time was non-trivial.

For shell-script test rig authors:

1. After any closing ) of a command substitution, the next character must be a newline (not another assignment, not a semicolon, not a space-then-assignment).
2. When adding a new test by copy-pasting an existing block and modifying, run bash -n script.sh AND visually verify the diff has no joined lines.
3. Prefer leaving a blank line between distinct test blocks. Visual separation makes joined-line bugs visible.

Future improvement: a CI lint rule that flags \)\w*= (close-paren immediately followed by an assignment) in .sh files would catch this mechanically. Defer per Use Only What Hurts; if the bug recurs, lint graduates from defer to active.

• Ritual Is a Smell — visual blank lines between tests are a low-cost pattern; CI lint is the durable fix when ritual breaks down