fix(tools/git): detect-platform died silently outside a repo, taking every wrapper with it (#1089)

packages/mosaic/framework/tools/git/detect-platform.sh

@@ -5,7 +5,10 @@
 
 detect_platform() {
     local remote_url
-    remote_url=$(git remote get-url origin 2>/dev/null)
+    # `|| true` is load-bearing under `set -e`: outside a git repo this returns 128 and
+    # kills the CALLER before the -z check below can run, so the error message that is
+    # already written here was unreachable. Same idiom as get_gitea_repo_args() below.
+    remote_url=$(git remote get-url origin 2>/dev/null) || true
 
     if [[ -z "$remote_url" ]]; then
         echo "error: not a git repository or no origin remote" >&2
@@ -39,7 +42,10 @@ detect_platform() {
 
 get_repo_info() {
     local remote_url
-    remote_url=$(git remote get-url origin 2>/dev/null)
+    # `|| true` is load-bearing under `set -e`: outside a git repo this returns 128 and
+    # kills the CALLER before the -z check below can run, so the error message that is
+    # already written here was unreachable. Same idiom as get_gitea_repo_args() below.
+    remote_url=$(git remote get-url origin 2>/dev/null) || true
 
     if [[ -z "$remote_url" ]]; then
         echo "error: not a git repository or no origin remote" >&2

packages/mosaic/framework/tools/git/test-detect-platform-outside-repo.sh

@@ -0,0 +1,58 @@
+#!/bin/bash
+# Regression: detect_platform / get_repo_info must FAIL LOUDLY outside a git repo,
+# not kill the caller silently.
+#
+# Both functions already contained the right error path:
+#     if [[ -z "$remote_url" ]]; then echo "error: not a git repository..." >&2; return 1; fi
+# but under `set -e` -- which every wrapper in this directory uses -- the preceding
+# assignment `remote_url=$(git remote get-url origin 2>/dev/null)` returns git's 128
+# outside a repo and terminates the CALLER first. The message was unreachable.
+#
+# Observed cost: pr-review.sh invoked from a non-repo cwd exits 128 with NO stdout and
+# NO stderr, even when -r/--repo and -H/--host are supplied -- the flags documented as
+# "skips git-remote inference". Two reviewer seats hit this and correctly reported
+# `blocked` with no diagnostic to report.
+#
+# The control that matters is the LOUD one: asserting "rc != 0" passes on the broken
+# build too, because 128 is also non-zero. The test must assert the MESSAGE.
+set -uo pipefail
+fail=0
+HERE="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+TMP="$(mktemp -d)"; trap 'rm -rf "$TMP"' EXIT
+
+run_outside() { # $1=function name -> "rc:sawmessage"
+    local fn="$1" out rc
+    out=$( cd "$TMP" && bash -c "set -e; source '$HERE/detect-platform.sh'; $fn" 2>&1 ); rc=$?
+    printf '%s:%s' "$rc" "$(grep -qi 'not a git repository' <<<"$out" && echo yes || echo no)"
+}
+check() { if [ "$2" = "$3" ]; then echo "  PASS  $1 ($2)"; else echo "  FAIL  $1: got $2, want $3"; fail=1; fi; }
+
+# $TMP must not be inside a git repo. Do not SKIP on failure: be-coder-07 showed the
+# original SKIP exited 0, so pointing TMPDIR beneath a git worktree made this test PASS
+# against unchanged main. A skip that exits 0 is indistinguishable from a pass.
+# GIT_CEILING_DIRECTORIES stops git walking above $TMP, making the condition hold
+# regardless of where TMPDIR lives, rather than merely detecting when it does not.
+# GIT_CEILING_DIRECTORIES is matched against the PHYSICAL path -- a symlinked TMPDIR
+# (/tmp is commonly one) makes the logical path never match, and the ceiling silently
+# does nothing. Resolve it before exporting.
+TMP="$(cd "$TMP" && pwd -P)"
+export GIT_CEILING_DIRECTORIES="$TMP"
+if ( cd "$TMP" && git rev-parse --git-dir >/dev/null 2>&1 ); then
+    echo "  FAIL  scratch dir is inside a git repo even with GIT_CEILING_DIRECTORIES set;"
+    echo "        the outside-a-repo precondition cannot be established -- refusing to report a result"
+    exit 1
+fi
+
+echo "== outside a git repo: rc=1 AND the diagnostic is emitted =="
+check "detect_platform" "$(run_outside detect_platform)" "1:yes"
+check "get_repo_info"   "$(run_outside get_repo_info)"   "1:yes"
+
+echo "== inside a git repo the functions still work =="
+git init -q "$TMP/repo" 2>/dev/null
+git -C "$TMP/repo" remote add origin https://git.mosaicstack.dev/mosaicstack/stack.git 2>/dev/null
+out=$( cd "$TMP/repo" && bash -c "set -e; source '$HERE/detect-platform.sh'; detect_platform" 2>&1 ); rc=$?
+if [ "$rc" -eq 0 ] && grep -qi 'gitea' <<<"$out"; then echo "  PASS  detect_platform in-repo (rc=0, $out)"
+else echo "  FAIL  detect_platform in-repo: rc=$rc out=$out"; fail=1; fi
+
+[ "$fail" -eq 0 ] && echo "OK  detect-platform fails loudly outside a repo" || echo "FAILED"
+exit "$fail"