Read the go.mod module directive through go_mod_edit and delete the crawler's unused parse_go_mod_module

[mikolalysenko]

[agent] Filed by the scheduled architecture audit routine (ecosystems and formats). Register: discussion #560 register.

Kind: refactor. Source: review Part 5.4 ("Go") and Part 6.4 (manifest table), register E19 (Go half).

Problem

The go.mod module directive has two hand-written readers (rows 1 and 2 below), and neither uses the directive walker that go_mod_edit already shares with the hosted rewriter and VEX discovery. Verified on 045d7ec:

Reader	Production callers	Grammar
crawlers/go_crawler.rs parse_go_mod_module	none. grep -rnw over the workspace, including socket-patch-node, finds it only in its own unit tests and tests/crawler_go_e2e.rs. Its last caller went away before 2463257.	first whitespace token; no BOM handling; no path-safety check
vex/product.rs parse_go_mod	VEX --product auto-detection (the PRODUCT_MANIFESTS probe at product.rs#L83)	strips a BOM; rejects module foo bar; runs is_safe_multi_segment
go_mod_edit for_each_directive_body / directive_body,`` with normalize_for_read	require and replace for hosted, vendored, agent apply and VEX	single-line and keyword ( … ) block forms, quoted tokens, any whitespace

They have drifted, proven by execution. Go accepts the block form of the directive: with go.mod = module (⏎\texample.com/blk⏎)⏎⏎go 1.21, go 1.24.7 list -m prints example.com/blk. A unit probe on the same text, run twice on 045d7ec (not committed), got:

• product::parse_go_mod → Some("pkg:golang/(")
• go_crawler::parse_go_mod_module → Some("(")
• control module example.com/m → both example.com/m

go_mod_edit's walker already handles the block form, because it is the same rule it uses for require ( … ).

Symptoms and impact

I found no open issue for this. A block-form module directive is rare, so the user-visible risk is low (a wrong --product purl on a valid project). The structural cost is a dead public function with two test files pinning it, and a third copy of go.mod lexing that will drift again whenever the shared walker changes.

Proposed change

1. Add go_mod_edit::module_path(text: &str) -> Option<String> built on normalize_for_read + for_each_directive_body(text, "module", …): the first body's first token, unquoted, rejected when empty or when is_safe_multi_segment fails.
2. Make vex/product.rs parse_go_mod call it and keep only the pkg:golang/<module> formatting.
3. Delete crawlers::go_crawler::parse_go_mod_module and its tests. Move the cases worth keeping (quoted path, module "", trailing comment, modulepath = x, module foo bar) to go_mod_edit's unit tests, and drop the parse_go_mod_module import from tests/crawler_go_e2e.rs.

Size and scope

vendor/go_mod_edit.rs (+15), vex/product.rs (−15), crawlers/go_crawler.rs (−45 prod, −35 test), tests/crawler_go_e2e.rs (−~30). Roughly −45 production lines net. Out of scope: moving go_mod_edit into formats/ (E20; #631 does this for go_sum_edit), and the other manifest probes in product.rs (E38).

Acceptance criteria

• parse_go_mod_module no longer exists. grep -rn 'strip_prefix("module")' crates finds nothing outside tests.
• New unit tests for module_path: single-line, quoted, trailing // comment, BOM, block form module ( … ), empty module "", module foo bar (→ None), modulepath = x (→ None), unsafe segments (→ None).
• A vex/product.rs test: a block-form go.mod yields pkg:golang/example.com/blk.
• cargo test -p socket-patch-core (including crawler_go_e2e) and the vex product tests stay green.

Dependencies

None; it can start now. If #631 lands first and moves the go codecs into formats/golang/, put module_path next to the go.mod reader wherever it lives then.

[mikolalysenko]

[agent] Triaged as priority:p2 (Go modules refactor). No duplicate or open PR found. It overlaps with #631's move of the go codecs; whichever change lands second should rebase onto the other.

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[mikolalysenko]

[agent] Claiming this issue for the architecture refactor routine (highest leverage: the top-ranked candidate whose files no open fix or refactor PR changes; it collapses three go.mod module readers into the shared go_mod_edit walker and fixes the block-form misread in VEX --product). Branch: arch-refactor/781-go-mod-module. Claim-ID: 2026-10-05T14:56:15Z-934ce5

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[mikolalysenko]

[agent] Draft PR: #870.

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