test: 100% Kotlin test coverage of the Android layer; fix regressions from #388

[tony19]

Summary

This PR adds Kotlin unit tests that cover every line and branch of the Android-specific layer (ch.qos.logback.{classic,core}.android), and a CI gate that keeps coverage there.

The tests were first written against the Java code that #388 replaced, then run against the Kotlin conversion to check it. They found regressions, which this PR also fixes.

Tests (test:)

• Ported to Kotlin: LogcatAppenderTest, SQLiteAppenderTest and AndroidContextUtilTest, keeping every original case.
• New: BasicLogcatConfiguratorTest, SystemClockTest and SystemPropertiesProxyTest.
• API check: JavaApiSignaturesTest pins the JVM-level API that Java callers and Joran rely on, so a binary-incompatible change fails a test.
• What the tests assert: observable behavior, such as logcat output, the rows written to SQLite, status messages, properties and exceptions. They don't just execute lines; review passes checked that mutated code fails them.
• Coverage: 178 tests. In a local Robolectric run with JaCoCo 0.8.15, coverage of the layer is 100%: 1810/1810 instructions, 246/246 branches, 344/344 lines.

Regressions from #388 fixed (fix:)

• Return type: SystemPropertiesProxy.getBoolean returned a primitive boolean instead of java.lang.Boolean, which is binary-incompatible for Java callers (NoSuchMethodError).
• Null keys: SystemPropertiesProxy.get and getBoolean threw on a null key instead of returning the default.
• Final members: the public members of AndroidContextUtil, LogcatAppender and SQLiteAppender had become final, which breaks subclasses that override them. They are open again.
• Dropped events: LogcatAppender dropped events without a logger name; they are logged with a null tag again.
• Pre-Lollipop check: AndroidContextUtil.getNoBackupFilesDirectoryPath lost its SDK check; it's restored.
• Unreachable null checks: removed so that every branch can be tested.

Kept as #388 changed them, since they're harmless:

• SQLiteAppender.finalize() is removed;
• blank filenames use isNullOrBlank;
• AndroidContextUtil.getContext() is public;
• BasicLogcatConfigurator is an object;
• SystemPropertiesProxy is final (its constructor is private);
• LogcatAppender falls back to the logger name when a tag layout produces no tag.

Build (build:)

• Coverage recording: JaCoCo 0.8.15 unit-test coverage via AGP's enableUnitTestCoverage, with includeNoLocationClasses so classes loaded by Robolectric are recorded.
• Gate: verifyAndroidLayerCoverage fails unless every class in the layer has 100% line and branch coverage.
  • CI runs it after the unit tests.
  • CI uploads the jdk11Debug report as the coverage-report artifact.
• Test dependencies: kotlin-test and mockito-kotlin 6.4.0.
• Kover was tried first and dropped: with AGP 9's variants it never attached the unit tests' coverage data to its reports, so it always reported 0%.

Architecture: no packages, runtime dependencies or published outputs change; docs/architecture/ is untouched.

Deferred work considered: the architecture-docs check failed on main after #388, which made Static Analysis fail here too. #480 fixed it on main, and this branch is rebased onto that fix.

🤖 Generated with Claude Code

https://claude.ai/code/session_01AN8SJNGETCegfBbPy4iV5K

[tony19]

Static Analysis (Checkstyle + PMD) fails at the ./scripts/check-architecture-docs.sh step, and the failure does not come from this PR. main has failed this check since #388 merged; see the Static Analysis runs for ffe4cf3 (#388) and e6aa6dd (#479).

The failing step reports:

docs/architecture/components.md: entries for packages that no longer exist under logback-android/src/main/java:
  ch/qos/logback/classic/android
  ch/qos/logback/core/android

Cause: the script, added in #478, only looks for packages under src/main/java, and #388 moved those two packages to src/main/kotlin. The catalogue entries themselves are still correct. The script's two dependency rules have the same gap: core must not import classic, and only allowed packages may import android.*. Kotlin sources are never checked against either rule.

No fix is open yet. This patch makes the script scan both source roots. I checked it locally against current main, where it prints "52 packages catalogued, dependency rules hold". I also added a temporary Kotlin file with a core→classic import and an android.* import; the patched script flags both.

--- a/scripts/check-architecture-docs.sh
+++ b/scripts/check-architecture-docs.sh
@@ -18,7 +18,9 @@ set -euo pipefail
 cd "$(dirname "$0")/.."
 
-SRC=logback-android/src/main/java
+# Library sources: the upstream-derived port is Java, the Android-specific
+# layer is Kotlin (#388). Package paths are relative to either root.
+SRC_ROOTS="logback-android/src/main/java logback-android/src/main/kotlin"
 CATALOGUE=docs/architecture/components.md
@@ -30,7 +32,15 @@
-packages=$(find "$SRC" -name '*.java' -exec dirname {} \; | sed "s|^$SRC/||" | sort -u)
+# Every Java/Kotlin source file, as a path relative to its source root.
+sources() {
+  for root in $SRC_ROOTS; do
+    [ -d "$root" ] || continue
+    find "$root" \( -name '*.java' -o -name '*.kt' \) | sed "s|^$root/||"
+  done
+}
+
+packages=$(sources | xargs -n1 dirname | sort -u)
@@ -43,19 +53,24 @@
-  echo "$CATALOGUE: entries for packages that no longer exist under $SRC:"
+  echo "$CATALOGUE: entries for packages that no longer exist under $SRC_ROOTS:"
@@
-core_to_classic=$(grep -rl 'import ch\.qos\.logback\.classic' "$SRC/ch/qos/logback/core" || true)
+core_to_classic=$(for root in $SRC_ROOTS; do
+  [ -d "$root/ch/qos/logback/core" ] && grep -rl 'import ch\.qos\.logback\.classic' "$root/ch/qos/logback/core"
+done || true)
@@
-android_users=$({ grep -rlE '^import (static )?android\.' "$SRC" || true; } | xargs -r -n1 dirname | sed "s|^$SRC/||" | sort -u)
+android_users=$(for root in $SRC_ROOTS; do
+  [ -d "$root" ] || continue
+  { grep -rlE '^import (static )?android\.' "$root" || true; } | xargs -r -n1 dirname | sed "s|^$root/||"
+done | sort -u)

The failure is deterministic, so re-running the job won't help. I've left the fix out of this PR to keep it scoped to tests and the coverage gate. It can go in as its own fix: PR, or be folded in here if you prefer.

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[tony19]

The architecture-docs failure is fixed on main: #480 made check-architecture-docs.sh scan src/main/kotlin as well, so the patch from my earlier comment isn't needed. I've rebased this branch onto current main, where the check passes: "52 packages catalogued, dependency rules hold".

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