# bincraft R-minor Enhancements Implementation Plan

> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.

**Goal:** Teach bincraft to (a) build/serve per-R-minor package indexes and (b) drive `process_cran_updates()` from the ABI classifier so only risky packages are built per R minor.

**Architecture:** Two additive, low-risk changes to the bincraft R package. `upload_package_index()` gains an `r_minor` argument so a per-minor slot (`…/contrib/<x.y>/`) gets its own `PACKAGES*`. `process_cran_updates()` gains `r_minor_detection`/`r_minor_sensitive_only` and classifies each candidate via `needs_per_minor_recompile()` (already in the package), passing a concrete `is_r_minor_sensitive` logical to the unchanged `build_binary_package()`.

**Tech Stack:** R package, `testthat` (3e) + `mockery` for tests, `roxygen2` for docs, `s3fs`/`cranlike` for the index. Repo: `https://codefloe.com/rpkgs/bincraft` (this plan is executed in a clone of that repo, NOT in build-cran-binaries).

**Pre-req:** PR #49 (ABI classifier) is already merged on `main`; `abi_classify()`, `needs_per_minor_recompile()`, `abi_risky_linking_deps()` are exported.

---

### Task 1: `package_index_remote_dir()` pure helper

**Files:**
- Modify: `R/package_index.R` (top of file, before `add_to_package_index`)
- Test: `tests/testthat/test-package_index.R` (new)

- [ ] **Step 1: Write the failing test**

```r
# tests/testthat/test-package_index.R
test_that("package_index_remote_dir builds the generic slot when r_minor is NULL", {
  expect_identical(
    package_index_remote_dir("bucket", "amd64", "alpine323"),
    file.path("bucket", "amd64", "alpine323", "latest", "src", "contrib")
  )
})

test_that("package_index_remote_dir appends the minor slot when r_minor is set", {
  expect_identical(
    package_index_remote_dir("bucket", "amd64", "alpine323", r_minor = "4.4"),
    file.path("bucket", "amd64", "alpine323", "latest", "src", "contrib", "4.4")
  )
})
```

- [ ] **Step 2: Run test to verify it fails**

Run: `R -q -e 'devtools::load_all("."); testthat::test_file("tests/testthat/test-package_index.R")'`
Expected: FAIL — `could not find function "package_index_remote_dir"`.

- [ ] **Step 3: Add the helper**

```r
# R/package_index.R — add near the top, above add_to_package_index()
#' Build the S3 remote contrib dir for a package index
#'
#' @param r_minor Optional `"major.minor"` string (e.g. `"4.4"`). When non-NULL
#'   the path points at the per-minor slot.
#' @keywords internal
package_index_remote_dir <- function(s3_bucket, arch, codename, r_minor = NULL) {
  base <- file.path(s3_bucket, arch, codename, "latest", "src", "contrib")
  if (is.null(r_minor)) {
    base
  } else {
    file.path(base, r_minor)
  }
}
```

- [ ] **Step 4: Run test to verify it passes**

Run: `R -q -e 'devtools::load_all("."); testthat::test_file("tests/testthat/test-package_index.R")'`
Expected: PASS (2/2).

- [ ] **Step 5: Commit**

```bash
git add R/package_index.R tests/testthat/test-package_index.R
git commit -m "feat(index): add package_index_remote_dir helper for per-minor slots"
```

---

### Task 2: per-minor support in `upload_package_index()`

**Files:**
- Modify: `R/package_index.R` (`upload_package_index`, signature + the `remote_bin_dir` block at lines ~117-124; `add_to_package_index` for consistency)

- [ ] **Step 1: Add `r_minor` to the signature and use the helper**

In `upload_package_index()`, add `r_minor = NULL` to the argument list (after `arch = NULL`). Replace the inline `remote_bin_dir <- file.path(s3_bucket, arch, codename, "latest", "src", "contrib")` block with:

```r
  remote_bin_dir <- package_index_remote_dir(s3_bucket, arch, codename, r_minor)
```

Do the same replacement in `add_to_package_index()` (it has the identical inline construction); add `r_minor = NULL` to its signature too.

- [ ] **Step 2: Add the roxygen param**

Above `upload_package_index` and `add_to_package_index`, add:

```r
#' @param r_minor Optional `"major.minor"` string. When set, the index is
#'   written/read under the per-minor slot `…/contrib/<r_minor>/` instead of the
#'   generic `…/contrib/` slot.
```

- [ ] **Step 3: Regenerate docs**

Run: `R -q -e 'devtools::document()'`
Expected: updated `man/upload_package_index.Rd`, `man/add_to_package_index.Rd`, no errors.

- [ ] **Step 4: Verify package still loads and existing tests pass**

Run: `R -q -e 'devtools::load_all("."); testthat::test_dir("tests/testthat")'`
Expected: PASS — no regressions; the new path test from Task 1 still green.

- [ ] **Step 5: Commit**

```bash
git add R/package_index.R man/
git commit -m "feat(index): upload/update PACKAGES for a per-minor slot via r_minor"
```

---

### Task 3: `classify_r_minor_sensitive()` internal helper

**Files:**
- Modify: `R/process_cran_updates.R` (add helper near the top)
- Test: `tests/testthat/test-process_cran_updates.R` (new)

- [ ] **Step 1: Write the failing test**

```r
# tests/testthat/test-process_cran_updates.R
test_that("classify_r_minor_sensitive returns TRUE for a risky package", {
  skip_if_not_installed("mockery")
  mockery::stub(classify_r_minor_sensitive, "clone_repository", function(pkg, tag, url, dest) {
    dir.create(dest, recursive = TRUE, showWarnings = FALSE)
    writeLines(
      c("Package: dummy", "Version: 1.0", "NeedsCompilation: yes", "LinkingTo: Rcpp"),
      file.path(dest, "DESCRIPTION")
    )
    dir.create(file.path(dest, "src"))
    writeLines("// Rcpp glue", file.path(dest, "src", "x.cpp"))
  })
  expect_true(classify_r_minor_sensitive("dummy", "1.0", "https://github.com/cran"))
})

test_that("classify_r_minor_sensitive returns FALSE for a pure-r package", {
  skip_if_not_installed("mockery")
  mockery::stub(classify_r_minor_sensitive, "clone_repository", function(pkg, tag, url, dest) {
    dir.create(dest, recursive = TRUE, showWarnings = FALSE)
    writeLines(c("Package: dummy", "Version: 1.0", "NeedsCompilation: no"),
      file.path(dest, "DESCRIPTION"))
  })
  expect_false(classify_r_minor_sensitive("dummy", "1.0", "https://github.com/cran"))
})

test_that("classify_r_minor_sensitive fails safe to TRUE on clone error", {
  skip_if_not_installed("mockery")
  mockery::stub(classify_r_minor_sensitive, "clone_repository", function(...) stop("boom"))
  expect_true(classify_r_minor_sensitive("dummy", "1.0", "https://github.com/cran"))
})
```

- [ ] **Step 2: Run test to verify it fails**

Run: `R -q -e 'devtools::load_all("."); testthat::test_file("tests/testthat/test-process_cran_updates.R")'`
Expected: FAIL — `could not find function "classify_r_minor_sensitive"`.

- [ ] **Step 3: Add the helper**

```r
# R/process_cran_updates.R — add above process_cran_updates()
#' Classify a single CRAN package for R-minor sensitivity
#'
#' Clones the package source to a temp dir and runs
#' [needs_per_minor_recompile()]. Fails safe to `TRUE` (build per minor) if the
#' clone or classification errors, so a possibly-ABI-fragile binary is never
#' served from the cross-minor generic slot by mistake.
#' @keywords internal
classify_r_minor_sensitive <- function(
  package_name,
  tag,
  source_org_url = "https://github.com/cran",
  local_clone_dir = tempdir()
) {
  dest <- file.path(
    local_clone_dir,
    sprintf("classify_%s_%s", package_name, tag)
  )
  on.exit(unlink(dest, recursive = TRUE, force = TRUE), add = TRUE)
  tryCatch(
    {
      clone_repository(package_name, tag, source_org_url, dest)
      isTRUE(as.logical(needs_per_minor_recompile(dest)))
    },
    error = function(e) {
      log_warn(sprintf(
        "{.fun classify_r_minor_sensitive}: failed for {.pkg %s} {.field %s}: %s. Treating as r-minor-sensitive.", # nolint
        package_name,
        tag,
        conditionMessage(e)
      ))
      TRUE
    }
  )
}
```

- [ ] **Step 4: Run test to verify it passes**

Run: `R -q -e 'devtools::load_all("."); testthat::test_file("tests/testthat/test-process_cran_updates.R")'`
Expected: PASS (3/3).

- [ ] **Step 5: Commit**

```bash
git add R/process_cran_updates.R tests/testthat/test-process_cran_updates.R
git commit -m "feat(updates): add classify_r_minor_sensitive helper"
```

---

### Task 4: wire classifier detection into `process_cran_updates()`

**Files:**
- Modify: `R/process_cran_updates.R` (`process_cran_updates` signature + the build loop at lines ~262-289)
- Modify: `tests/testthat/test-process_cran_updates.R` (add routing tests)

- [ ] **Step 1: Write the failing tests**

```r
# append to tests/testthat/test-process_cran_updates.R
test_that("classifier mode passes per-package is_r_minor_sensitive to build", {
  skip_if_not_installed("mockery")
  recorded <- list()
  mockery::stub(process_cran_updates, "get_updated_cran_packages",
    function(...) data.frame(name = c("riskypkg", "purepkg"),
                             version = c("1.0", "2.0"), stringsAsFactors = FALSE))
  mockery::stub(process_cran_updates, "get_new_cran_packages",
    function(...) data.frame(name = character(), version = character()))
  mockery::stub(process_cran_updates, "tools::CRAN_package_db",
    function(...) data.frame(Package = character(), OS_type = character()))
  mockery::stub(process_cran_updates, "classify_r_minor_sensitive",
    function(name, tag, ...) name == "riskypkg")
  mockery::stub(process_cran_updates, "build_binary_package",
    function(name, tag, ..., is_r_minor_sensitive) {
      recorded[[name]] <<- is_r_minor_sensitive
      invisible(TRUE)
    })

  process_cran_updates(
    platform = "alpine-323", process_removed = FALSE,
    r_minor_detection = "classifier",
    s3_endpoint = "x", s3_region = "x", s3_bucket = "x"
  )

  expect_true(recorded[["riskypkg"]])
  expect_false(recorded[["purepkg"]])
})

test_that("r_minor_sensitive_only drops non-risky candidates", {
  skip_if_not_installed("mockery")
  built <- character()
  mockery::stub(process_cran_updates, "get_updated_cran_packages",
    function(...) data.frame(name = c("riskypkg", "purepkg"),
                             version = c("1.0", "2.0"), stringsAsFactors = FALSE))
  mockery::stub(process_cran_updates, "get_new_cran_packages",
    function(...) data.frame(name = character(), version = character()))
  mockery::stub(process_cran_updates, "tools::CRAN_package_db",
    function(...) data.frame(Package = character(), OS_type = character()))
  mockery::stub(process_cran_updates, "classify_r_minor_sensitive",
    function(name, tag, ...) name == "riskypkg")
  mockery::stub(process_cran_updates, "build_binary_package",
    function(name, tag, ..., is_r_minor_sensitive) { built <<- c(built, name); invisible(TRUE) })

  process_cran_updates(
    platform = "alpine-323", process_removed = FALSE,
    r_minor_detection = "classifier", r_minor_sensitive_only = TRUE,
    s3_endpoint = "x", s3_region = "x", s3_bucket = "x"
  )

  expect_identical(built, "riskypkg")
})
```

- [ ] **Step 2: Run tests to verify they fail**

Run: `R -q -e 'devtools::load_all("."); testthat::test_file("tests/testthat/test-process_cran_updates.R")'`
Expected: FAIL — `unused argument (r_minor_detection = ...)`.

- [ ] **Step 3: Add the parameters**

In the `process_cran_updates()` signature, after `filter_r_minor_sensitive = FALSE,` add:

```r
  r_minor_detection = c("none", "issue", "classifier"),
  r_minor_sensitive_only = FALSE,
```

Immediately after the three `stop()` validation lines at the top of the body, add:

```r
  r_minor_detection <- match.arg(r_minor_detection)
  # back-compat: the old boolean maps onto the issue-list path
  if (isTRUE(filter_r_minor_sensitive) && r_minor_detection == "none") {
    r_minor_detection <- "issue"
  }
```

- [ ] **Step 4: Replace the issue-filter gate**

The existing block reads `if (filter_r_minor_sensitive) { all_pkgs <- get_r_minor_sensitive_packages(...) }`. Change its condition to:

```r
  if (r_minor_detection == "issue") {
    all_pkgs <- get_r_minor_sensitive_packages(
      r_minor_packages_forge_type,
      r_minor_packages_issue_url,
      interval,
      updated_packages = updated_pkgs,
      new_packages = new_pkgs
    )
  }
```

Also change the two later `if (filter_r_minor_sensitive)` log branches to `if (r_minor_detection != "none")`.

- [ ] **Step 5: Replace the build loop**

Replace the `purrr::walk2(all_pkgs$name, all_pkgs$version, ~ { build_binary_package(... is_r_minor_sensitive = filter_r_minor_sensitive ...) })` block with:

```r
    if (nrow(all_pkgs) > 0L) {
      sensitive <- switch(
        r_minor_detection,
        classifier = vapply(
          seq_len(nrow(all_pkgs)),
          function(i) {
            classify_r_minor_sensitive(
              all_pkgs$name[i],
              all_pkgs$version[i],
              local_clone_dir = local_clone_dir
            )
          },
          logical(1L)
        ),
        issue = rep(TRUE, nrow(all_pkgs)),
        none = rep(FALSE, nrow(all_pkgs))
      )

      if (isTRUE(r_minor_sensitive_only)) {
        all_pkgs <- all_pkgs[sensitive, , drop = FALSE]
        sensitive <- sensitive[sensitive]
      }

      purrr::pwalk(
        list(all_pkgs$name, all_pkgs$version, sensitive),
        function(.name, .version, .sensitive) {
          build_binary_package(
            .name,
            .version,
            platform = platform,
            upload = upload,
            archive = archive,
            force = force,
            store_build_metadata = store_build_metadata,
            s3_endpoint = s3_endpoint,
            s3_bucket = s3_bucket,
            s3_region = s3_region,
            s3_access_key_id = s3_access_key_id,
            s3_secret_access_key = s3_secret_access_key,
            is_r_minor_sensitive = .sensitive,
            metadata_db_type = metadata_db_type,
            metadata_db_host = metadata_db_host,
            metadata_db_name = metadata_db_name,
            metadata_db_table = metadata_db_table,
            metadata_db_port = metadata_db_port,
            metadata_db_user = metadata_db_user,
            metadata_db_password = metadata_db_password,
            metadata_db_sslmode = metadata_db_sslmode
          )
        }
      )
    } else {
      log_info("No packages to process after filtering Windows-only packages")
    }
```

- [ ] **Step 6: Run tests to verify they pass**

Run: `R -q -e 'devtools::load_all("."); testthat::test_file("tests/testthat/test-process_cran_updates.R")'`
Expected: PASS (5/5 — 3 from Task 3 + 2 new).

- [ ] **Step 7: Commit**

```bash
git add R/process_cran_updates.R tests/testthat/test-process_cran_updates.R
git commit -m "feat(updates): classifier-driven per-package r-minor routing + sensitive-only pass"
```

---

### Task 5: docs, roxygen params, version bump, NEWS

**Files:**
- Create: `man-roxygen/param-r_minor_detection.R`, `man-roxygen/param-r_minor_sensitive_only.R`
- Modify: `R/process_cran_updates.R` (roxygen `@template` lines), `DESCRIPTION`, `NEWS.md`

- [ ] **Step 1: Add the man templates**

```r
# man-roxygen/param-r_minor_detection.R
#' @param r_minor_detection How to decide which packages are R-minor-sensitive.
#'   `"none"` (default) builds everything into the generic slot. `"issue"` uses
#'   the curated tracking issue (the legacy `filter_r_minor_sensitive` path).
#'   `"classifier"` classifies each candidate via [needs_per_minor_recompile()]
#'   and routes only `risky` packages to the per-minor slot.
```

```r
# man-roxygen/param-r_minor_sensitive_only.R
#' @param r_minor_sensitive_only When `TRUE`, only R-minor-sensitive packages are
#'   built (used for the additional per-minor passes under non-primary R versions).
```

- [ ] **Step 2: Reference the templates**

In the roxygen block above `process_cran_updates`, add:

```r
#' @template param-r_minor_detection
#' @template param-r_minor_sensitive_only
```

- [ ] **Step 3: Bump version and NEWS**

In `DESCRIPTION` set `Version: 4.2.0`. Add to the top of `NEWS.md`:

```markdown
# bincraft 4.2.0

* `process_cran_updates()` gains `r_minor_detection` (`"none"`/`"issue"`/`"classifier"`)
  and `r_minor_sensitive_only`, classifying each candidate via the ABI classifier and
  routing only `risky` packages to per-minor slots.
* `upload_package_index()` / `add_to_package_index()` gain an `r_minor` argument to
  write/serve a per-minor `PACKAGES*` index under `…/contrib/<x.y>/`.
```

- [ ] **Step 4: Regenerate docs and run full check**

Run: `R -q -e 'devtools::document()'`
Run: `R -q -e 'devtools::test()'`
Expected: docs regenerate clean; all tests PASS.

- [ ] **Step 5: Commit, push, open PR**

```bash
git add DESCRIPTION NEWS.md man-roxygen/ man/ R/process_cran_updates.R
git commit -m "docs(release): bincraft 4.2.0 — per-minor index + classifier-driven updates"
git push -u origin <branch>
fj -H codefloe.com pr create --base main --head <branch> --body "<summary>" "feat: per-minor index + classifier-driven r-minor builds (4.2.0)"
```

---

## Self-Review

- **Spec coverage:** §"Required bincraft enhancements" item 1 (process_cran_updates) → Tasks 3-5; item 2 (upload_package_index per-minor) → Tasks 1-2. `build_binary_package` unchanged per the spec — no task, correct.
- **Type consistency:** helper named `package_index_remote_dir` (Tasks 1-2), `classify_r_minor_sensitive` (Tasks 3-4) consistently; params `r_minor_detection`/`r_minor_sensitive_only`/`r_minor` consistent across signature, tests, and docs.
- **Placeholders:** none — every code/edit step shows the actual code; `<branch>`/`<summary>` in the final push step are deliberate operator inputs.
- **Release dependency:** the pipeline plan pins bincraft `4.2.0`, matching the bump here.