fix: unbreak main, a compile error and an empty xcodebuild argument

.github/workflows/macos-tests.yml

@@ -302,17 +302,27 @@ jobs:
       - name: Run unit tests
         run: |
           set -o pipefail
+          # To a file on its own line, not through a process substitution. `< <(...)` discards the
+          # producer's exit status, so the script refusing an entry that would skip nothing printed
+          # its diagnostic, exited 1, and the step carried on to run the whole suite unskipped and
+          # report success. The refusal the comment above promises never once failed a job.
+          SKIP_FILE="${RUNNER_TEMP:-.}/quarantine-skip-args.txt"
+          scripts/ci/quarantine-args.sh .github/macos-test-quarantine.txt TableProTests "$XCTESTRUN" "$TEST_DESTINATION" > "$SKIP_FILE"
           # A read loop, not mapfile: the macOS runner's /bin/bash is 3.2, which has neither
           # mapfile nor readarray, and a `run:` block gets that bash.
           SKIP_ARGS=()
           while IFS= read -r arg; do
+            # A blank line would become a literal empty argument, and xcodebuild reads that as a
+            # build action and refuses the whole run. An empty array expands to nothing and is
+            # fine; one empty string is not.
+            [ -n "$arg" ] || continue
             SKIP_ARGS+=("$arg")
-          done < <(scripts/ci/quarantine-args.sh .github/macos-test-quarantine.txt TableProTests "$XCTESTRUN" "$TEST_DESTINATION")
+          done < "$SKIP_FILE"
           xcodebuild test-without-building \
             -xctestrun "$XCTESTRUN" \
             -destination "$TEST_DESTINATION" \
             -only-testing:TableProTests \
-            "${SKIP_ARGS[@]}" \
+            ${SKIP_ARGS[@]+"${SKIP_ARGS[@]}"} \
             -parallel-testing-enabled NO \
             -resultBundlePath TestResults.xcresult \
             | xcbeautify --renderer github-actions
@@ -380,17 +390,22 @@ jobs:
           SHARD_COUNT: ${{ matrix.of }}
         run: |
           set -o pipefail
+          # To a file on its own line, so a failure of the lister fails the step. A process
+          # substitution discards its exit status, which reads here as "the shard selected nothing".
+          ONLY_FILE="${RUNNER_TEMP:-.}/shard-only-args.txt"
+          scripts/ci/list-tests.sh \
+            --xctestrun "$XCTESTRUN" \
+            --target TableProUITests \
+            --quarantine .github/macos-ui-test-quarantine.txt \
+            --shard "$SHARD/$SHARD_COUNT" > "$ONLY_FILE"
           # A read loop, not mapfile: the macOS runner's /bin/bash is 3.2, which has neither.
           ONLY_ARGS=()
           while IFS= read -r arg; do
+            # The count check below cannot see an empty argument: one blank line makes the count 1
+            # and xcodebuild then reads that empty argument as a build action.
+            [ -n "$arg" ] || continue
             ONLY_ARGS+=("$arg")
-          done < <(
-            scripts/ci/list-tests.sh \
-              --xctestrun "$XCTESTRUN" \
-              --target TableProUITests \
-              --quarantine .github/macos-ui-test-quarantine.txt \
-              --shard "$SHARD/$SHARD_COUNT"
-          )
+          done < "$ONLY_FILE"
           [ "${#ONLY_ARGS[@]}" -gt 0 ] || { echo "::error::shard $SHARD selected no cases"; exit 1; }
           echo "shard $SHARD of $SHARD_COUNT runs ${#ONLY_ARGS[@]} cases"
           xcodebuild test-without-building \

.github/workflows/repo-hygiene.yml

@@ -83,6 +83,13 @@ jobs:
       - name: Validate the registry update script
         run: python3 .github/scripts/test_update_registry.py
 
+      # The macOS suite cannot catch this one: the script runs before any test does, and when it
+      # gets this wrong no test runs at all. An empty quarantine list made it print a blank line,
+      # which the caller turned into an empty xcodebuild argument, and main went red for three
+      # commits with `Unknown build action ''`.
+      - name: Validate the test quarantine script
+        run: python3 scripts/ci/test_quarantine_args.py
+
       # A check that guarded a real invariant and ran nowhere. Pure grep over Swift sources, so it
       # belongs on the free Linux runner. The MongoDB filter-shape check is the other one that was
       # orphaned, but it compiles a C probe against Libs/libbson, so it lives in the macOS build

TablePro/Views/Main/EditorTabStripSurfaces.swift

@@ -23,7 +23,12 @@ internal enum EditorTabStripPalette {
     internal static var selectedFill: Color { Color(nsColor: .controlColor) }
     /// Half the weight of a separator. `separatorColor` was twice the measured edge and read as a
     /// drawn outline rather than the lit rim the system puts there.
-    internal static var trackEdge: Color { Color(nsColor: .quinaryLabelColor) }
+    ///
+    /// `quinaryLabel`, not `quinaryLabelColor`. The two spellings swap places between toolchains:
+    /// the Xcode 27 beta deprecates this one in favour of `quinaryLabelColor`, and Xcode 26.4, the
+    /// one CI builds with, rejects `quinaryLabelColor` outright as renamed to this. Take the
+    /// spelling CI accepts and ignore the beta's deprecation hint.
+    internal static var trackEdge: Color { Color(nsColor: .quinaryLabel) }
     internal static var hoverFill: Color { Color(nsColor: .tertiarySystemFill) }
     internal static var separator: Color { Color(nsColor: .separatorColor) }
 }

scripts/ci/quarantine_args.py

@@ -69,7 +69,14 @@ def main():
 
     if not ok:
         sys.exit(1)
-    print("\n".join(args))
+
+    # Nothing at all when there is nothing to skip, because `print("")` is a blank line and the
+    # caller reads this stdout one line per argument. An empty list therefore reached xcodebuild as
+    # a literal empty argument and it stopped with `Unknown build action ''` before running a
+    # single test. An empty quarantine file is the goal, not an edge case: main went red the
+    # commit the last entry was removed and stayed red.
+    if args:
+        print("\n".join(args))
 
 
 if __name__ == "__main__":

scripts/ci/test_quarantine_args.py

@@ -0,0 +1,106 @@
+#!/usr/bin/env python3
+"""Tests for quarantine_args.py, whose stdout is read one line per xcodebuild argument.
+
+Run: python3 scripts/ci/test_quarantine_args.py
+
+The first test is the one that matters. `print("\\n".join([]))` is a blank line, the caller turns
+every line into an argument, and xcodebuild reads an empty argument as a build action: `Unknown
+build action ''`, exit 65, before a single test runs. An empty quarantine file is the goal the file
+itself states, so main went red the commit the last entry was removed and stayed red for three
+commits.
+"""
+import importlib.util
+import io
+import json
+import os
+import sys
+import tempfile
+from contextlib import redirect_stdout
+
+_spec = importlib.util.spec_from_file_location(
+    "quarantine_args",
+    os.path.join(os.path.dirname(__file__), "quarantine_args.py"),
+)
+quarantine_args = importlib.util.module_from_spec(_spec)
+_spec.loader.exec_module(quarantine_args)
+
+ENUMERATED = ["TableProTests/SomeSuite/someCase()", "TableProTests/OtherSuite/otherCase()"]
+
+
+def _run(quarantine_text, identifiers=None):
+    """Returns (stdout, exit code or None), the way the shell caller sees it."""
+    with tempfile.TemporaryDirectory() as work:
+        quarantine = os.path.join(work, "quarantine.txt")
+        with open(quarantine, "w", encoding="utf-8") as handle:
+            handle.write(quarantine_text)
+
+        enumeration = os.path.join(work, "tests.json")
+        listed = ENUMERATED if identifiers is None else identifiers
+        with open(enumeration, "w", encoding="utf-8") as handle:
+            json.dump({"values": [{"enabledTests": [{"identifier": i} for i in listed]}]}, handle)
+
+        os.environ["QUARANTINE"] = quarantine
+        os.environ["TARGET"] = "TableProTests"
+        argv = sys.argv
+        sys.argv = ["quarantine_args.py", enumeration]
+        captured = io.StringIO()
+        status = None
+        try:
+            with redirect_stdout(captured):
+                quarantine_args.main()
+        except SystemExit as error:
+            status = error.code
+        finally:
+            sys.argv = argv
+        return captured.getvalue(), status
+
+
+def test_an_empty_list_prints_nothing_at_all():
+    """Not even a newline. One blank line is one empty argument, and xcodebuild refuses the run."""
+    out, status = _run("# every entry has been burned down\n#\n")
+    assert out == "", repr(out)
+    assert status is None, status
+
+
+def test_a_file_of_only_whitespace_prints_nothing():
+    out, status = _run("\n   \n\t\n")
+    assert out == "", repr(out)
+    assert status is None, status
+
+
+def test_no_line_is_ever_empty():
+    """The caller reads one argument per line, so a blank one is unrepresentable by construction."""
+    out, _ = _run("SomeSuite/someCase()\nOtherSuite/otherCase()\n")
+    assert out.splitlines() == [
+        "-skip-testing:TableProTests/SomeSuite/someCase()",
+        "-skip-testing:TableProTests/OtherSuite/otherCase()",
+    ], out
+    assert all(line.strip() for line in out.splitlines()), repr(out)
+
+
+def test_a_whole_suite_is_accepted_without_a_case():
+    out, _ = _run("SomeSuite\n")
+    assert out.splitlines() == ["-skip-testing:TableProTests/SomeSuite"], out
+
+
+def test_an_entry_that_would_skip_nothing_still_fails_the_job():
+    """The guard the script exists for, unchanged by the empty-list fix."""
+    out, status = _run("NoSuchSuite/nope()\n")
+    assert status == 1, status
+    assert out == "", repr(out)
+
+
+def test_a_swift_testing_case_without_its_parentheses_still_fails():
+    out, status = _run("SomeSuite/someCase\n")
+    assert status == 1, status
+    assert out == "", repr(out)
+
+
+if __name__ == "__main__":
+    test_an_empty_list_prints_nothing_at_all()
+    test_a_file_of_only_whitespace_prints_nothing()
+    test_no_line_is_ever_empty()
+    test_a_whole_suite_is_accepted_without_a_case()
+    test_an_entry_that_would_skip_nothing_still_fails_the_job()
+    test_a_swift_testing_case_without_its_parentheses_still_fails()
+    print("All quarantine-args tests passed.")