Increase test coverage to 95% and fix merge-queue merge driver (plan 85)

[jeduden]

Summary

• Reaches 95%+ combined unit + e2e test coverage (up from 89.4%) by adding targeted edge-case and error-path tests across rule packages and core packages
• Extracts shared helpers (settings.ToInt/ToFloat, astutil.HeadingLine/ParagraphLine) to eliminate duplicated private functions across 14 rule packages
• Installs the mdsmith merge driver in the merge-queue workflow so PLAN.md catalog conflicts auto-resolve during batch branch creation

Changes

Shared helpers (phases 1–2)

• internal/rules/settings — ToInt, ToFloat, ToStringSlice with 100% coverage, replacing private copies in 10 + 4 rule packages
• internal/rules/astutil — HeadingLine, ParagraphLine, IsTable, HeadingText, ExtractText with 100% coverage, replacing private copies in 4 + 3 + 2 rule packages

Coverage tests (phases 3–5)

New and expanded tests covering previously uncovered branches in: archetype/gensection, config, fix, lint, metrics, query, rule, rules/catalog, rules/concisenessscoring, rules/concisenessscoring/classifier, rules/crossfilereferenceintegrity, rules/directorystructure, rules/emptysectionbody, rules/fencedcodestyle, rules/firstlineheading, rules/headingstyle, rules/include, rules/linelength, rules/listindent, rules/requiredstructure, rules/ruledocs, rules/tableformat, rules/tablereadability

CI fix

• merge-queue.yml — installs the mdsmith merge driver before the merge-queue action using the pinned v0.5.0 release binary (downloaded via curl with SHA256 verification). A release binary is used intentionally: the merge-queue workflow runs with MERGE_QUEUE_TOKEN and labeling a PR can trigger it, so executing untrusted PR code in that context would be a token exfiltration risk. The merge driver here handles generated-section conflicts (PLAN.md/README.md); testing merge driver code changes is the job of CI, not the merge queue.

Plan

• Plan 85 marked ✅; all acceptance criteria met

Test plan

• go test ./... passes
• go tool golangci-lint run reports no issues
• Combined unit + e2e coverage: 95.1%

https://claude.ai/code/session_01DvP5H17ofGpHmR7DhSU438

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.24%. Comparing base (cbf8a6b) to head (d1febe6).
⚠️ Report is 38 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #172      +/-   ##
==========================================
+ Coverage   89.69%   93.24%   +3.55%     
==========================================
  Files         113      113              
  Lines       12163    12202      +39     
==========================================
+ Hits        10909    11378     +469     
+ Misses        796      498     -298     
+ Partials      458      326     -132     

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[Copilot]

Pull request overview

This PR focuses on raising overall repository test coverage to 95% by adding new tests and expanding existing ones across many rule packages and a few core/internal packages (fix, lint, config, metrics, query).

Changes:

• Added multiple new “more coverage” / “coverage” test files to exercise previously uncovered branches and error paths.
• Expanded many existing rule test suites with extra branch/edge-case scenarios (including Category() coverage).
• Marked the coverage plan (Plan 85) as completed and updated ignore patterns for coverage artifacts.

Reviewed changes

Copilot reviewed 42 out of 43 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
plan/85_coverage-to-95-percent.md	Marks the coverage plan as completed and checks off acceptance criteria.
internal/rules/tablereadability/rule_coverage_test.go	Adds branch-coverage tests for table parsing and column width ratio edge cases.
internal/rules/tableformat/rule_test.go	Adds a simple Category() coverage test.
internal/rules/tableformat/rule_morecoverage_test.go	New file with Fix/parse/prefix formatting edge-case tests.
internal/rules/singletrailingnewline/rule_test.go	Adds Category() coverage test.
internal/rules/ruledocs_test.go	Adds additional tests around FS/error paths and front matter stripping/parsing.
internal/rules/requiredstructure/rule_test.go	Adds extensive branch coverage for schema/front-matter validation, includes, and sync logic.
internal/rules/notrailingspaces/rule_test.go	Adds Category() coverage test.
internal/rules/nomultipleblanks/rule_test.go	Adds Category() coverage test.
internal/rules/nohardtabs/rule_test.go	Adds Category() coverage test.
internal/rules/noemptyalttext/rule_test.go	Adds Category() coverage test.
internal/rules/noemphasisasheading/rule_test.go	Adds Category() coverage test.
internal/rules/nobareurls/rule_test.go	Adds Category() coverage test.
internal/rules/listindent/rule_test.go	Adds Category() coverage test.
internal/rules/listindent/rule_coverage_test.go	Adds Fix/defaulting and AST traversal edge-case tests.
internal/rules/linelength/rule_test.go	Adds Category() coverage test.
internal/rules/include/rule_test.go	Adds Category() coverage test.
internal/rules/headingstyle/rule_test.go	Adds explicit Category() expectation for heading-style.
internal/rules/headingstyle/rule_morecoverage_test.go	New file adding coverage for heading detection and byte-range logic.
internal/rules/headingstyle/explore3_test.go	New exploratory tests around manual AST construction.
internal/rules/firstlineheading/rule_test.go	Adds Category() test plus branch coverage for nil/empty AST cases.
internal/rules/fencedcodestyle/rule_coverage_test.go	Adds coverage for fence replacement and fence-open range edge cases.
internal/rules/fencedcodelanguage/rule_test.go	Adds Category() coverage test.
internal/rules/emptysectionbody/rule_test.go	Adds many coverage tests for settings parsing, AST edge cases, and content detection.
internal/rules/directorystructure/rule_test.go	Adds branch coverage for settings validation and formatting helpers.
internal/rules/crossfilereferenceintegrity/rule_test.go	Adds tests for anchor caching, FS-only resolution, and parsing helpers.
internal/rules/crossfilereferenceintegrity/rule_morecoverage_test.go	New file with additional parsing/path-filter/link-position/size-limit tests.
internal/rules/concisenessscoring/rule_test.go	Adds branch coverage for settings errors and scorer-load error paths; adds embedded scorer success test.
internal/rules/concisenessscoring/classifier/model_test.go	Adds helpers and many tests for lexicon/model validation and phrase/token matching branches.
internal/rules/catalog/wrap_test.go	Adds wrap/breakpoint/span parsing edge-case tests.
internal/rules/catalog/rule_test.go	Adds coverage for generation/read errors, include cycle checks, exclusions, and sort-value validation.
internal/rules/blanklinearoundfencedcode/rule_test.go	Adds Category() expectation test.
internal/rule/registry_test.go	Adds Reset() behavior coverage.
internal/query/query_test.go	Adds tests to exercise collectPaths and json.Marshal error handling.
internal/metrics/metrics_morecoverage_test.go	New file adding coverage for parsing, FS traversal errors, scoring, sorting, and Collect error paths.
internal/metrics/metrics_coverage_test.go	Adds tests for document caching and error propagation across File/PlainText/WordCount/HeadingCount.
internal/lint/lint_coverage_test.go	Adds coverage for root dir setup, ancestor .gitignore loading, and walk errors.
internal/fix/fix_coverage_test.go	Adds tests for diagnostic sorting, ignore handling, and atomic write failure behavior.
internal/config/config_test.go	Adds Merge/copy coverage and top-level YAML key parsing edge cases.
internal/archetype/gensection/parse_test.go	Adds coverage for param validation, column config parsing, and marker content extraction edge cases.
internal/archetype/gensection/engine_test.go	Adds Fix() behavior test for invalid YAML directive bodies.
PLAN.md	Updates plan table to show Plan 85 as complete.
.gitignore	Ignores additional coverage output artifacts (e2e and merged/unit coverage files).

[Copilot]

Pull request overview

Copilot reviewed 42 out of 43 changed files in this pull request and generated 4 comments.

[Copilot]

Pull request overview

Copilot reviewed 41 out of 42 changed files in this pull request and generated 3 comments.

[jeduden]

🟢 Merge Queue — picked up

This PR is in the queue and will be batched with other queue-labelled PRs.

Next: No action needed — you'll get another comment when CI starts on the batch. View merge queue run.

[jeduden]

⚠️ Merge Queue — merge conflict

This PR could not be merged into the batch branch without conflicts with main or another queued PR.

Next: Rebase onto or merge main into your branch, resolve conflicts, push, then re-add the queue label.

[Copilot]

Pull request overview

Copilot reviewed 43 out of 44 changed files in this pull request and generated 3 comments.

Comments suppressed due to low confidence (1)

cmd/mdsmith/mergedriver.go:410

• driver := exe + " merge-driver run ..." builds a shell command without quoting/escaping the executable path. If exe contains spaces (common on Windows, e.g. under "Program Files"), git will split it and the merge driver won’t run. Consider shell-quoting/escaping exe when constructing the driver command (and test on paths with spaces).

	exe, err := resolveInstalledBinary()
	if err != nil {
		return fmt.Errorf("cannot locate mdsmith binary: %w", err)
	}
	driver := exe + " merge-driver run %O %A %B %P"
	cmds := [][]string{
		{"git", "config", "merge.mdsmith.name",
			"mdsmith section-aware Markdown merge"},
		{"git", "config", "merge.mdsmith.driver", driver},

[Copilot]

Pull request overview

Copilot reviewed 45 out of 46 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 47 out of 48 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 47 out of 48 changed files in this pull request and generated 2 comments.

[jeduden]

🟢 Merge Queue — picked up

This PR is in the queue and will be batched with other queue-labelled PRs.

Next: No action needed — you'll get another comment when CI starts on the batch. View merge queue run.

[jeduden]

🔵 Merge Queue — CI running

Merged into batch branch merge-queue/batch-172-1777222071. View CI run.

Next: No action needed — you'll be notified when CI completes.

[jeduden]

✅ Merge Queue — merged

This PR landed on main via commit ada7dc2. CI run that validated the merge.

Next: Done — nothing more to do here.