Refactor the test harness for external repo tests (#1994)

- Use CTest labels to filter tests ("internal"/"external", "free"/"nonfree",
  and individual tool+project names) instead of defining `TESTS_RUN_NONFREE`
- Allow each external test to run independently in CTest
- Remove the unused no-op `fetch-test-deps.sh --only-internal` option

test/external/gb-starter-kit.cfg

@@ -0,0 +1,7 @@
+EXTERNAL_TEST_OWNER=ISSOtm
+EXTERNAL_TEST_REPO=gb-starter-kit
+EXTERNAL_TEST_DOMAIN=codeberg.org
+EXTERNAL_TEST_COMMIT=74b647d62ff74b40d2b52e585cbebe148463212e
+EXTERNAL_TEST_TARGET=all
+EXTERNAL_TEST_FILE=bin/boilerplate.gb
+EXTERNAL_TEST_HASH=b4f130169ba73284e0d0e71b53e7baa4eca2f7fe

test/external/ladx.cfg

@@ -0,0 +1,7 @@
+EXTERNAL_TEST_OWNER=zladx
+EXTERNAL_TEST_REPO=LADX-Disassembly
+EXTERNAL_TEST_DOMAIN=github.com
+EXTERNAL_TEST_COMMIT=c77af4473e7a877c68e1de34a2aaf80e9076dc35
+EXTERNAL_TEST_TARGET=default
+EXTERNAL_TEST_FILE=azle.gbc
+EXTERNAL_TEST_HASH=d90ac17e9bf17b6c61624ad9f05447bdb5efc01a

test/external/libbet.cfg

@@ -0,0 +1,7 @@
+EXTERNAL_TEST_OWNER=pinobatch
+EXTERNAL_TEST_REPO=libbet
+EXTERNAL_TEST_DOMAIN=github.com
+EXTERNAL_TEST_COMMIT=e42c0036b18e6e715987b88b4973389b283974c9
+EXTERNAL_TEST_TARGET=all
+EXTERNAL_TEST_FILE=libbet.gb
+EXTERNAL_TEST_HASH=f117089aa056600e2d404bbcbac96b016fc64611

test/external/pokecrystal.cfg

@@ -0,0 +1,7 @@
+EXTERNAL_TEST_OWNER=pret
+EXTERNAL_TEST_REPO=pokecrystal
+EXTERNAL_TEST_DOMAIN=github.com
+EXTERNAL_TEST_COMMIT=2bbb15675de0d2bbebc8cc9978f5c7fb15bc73b9
+EXTERNAL_TEST_TARGET=compare
+EXTERNAL_TEST_FILE=pokecrystal.gbc
+EXTERNAL_TEST_HASH=f4cd194bdee0d04ca4eac29e09b8e4e9d818c133

test/external/pokered.cfg

@@ -0,0 +1,7 @@
+EXTERNAL_TEST_OWNER=pret
+EXTERNAL_TEST_REPO=pokered
+EXTERNAL_TEST_DOMAIN=github.com
+EXTERNAL_TEST_COMMIT=0555b42dc0ceffaae613e97cc0cf2e8c0b45013c
+EXTERNAL_TEST_TARGET=compare
+EXTERNAL_TEST_FILE=pokered.gbc
+EXTERNAL_TEST_HASH=ea9bcae617fdf159b045185467ae58b2e4a48b9a

test/external/sameboy.cfg

@@ -0,0 +1,7 @@
+EXTERNAL_TEST_OWNER=LIJI32
+EXTERNAL_TEST_REPO=SameBoy
+EXTERNAL_TEST_DOMAIN=github.com
+EXTERNAL_TEST_COMMIT=2f4a6f231ec40ecfc0ab7df0a09eb932e7ccddec
+EXTERNAL_TEST_TARGET=bootroms
+EXTERNAL_TEST_FILE=build/bin/BootROMs/cgb_boot.bin
+EXTERNAL_TEST_HASH=113903775a9d34b798c2f8076672da6626815a91

test/external/test.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+export LC_ALL=C
+
+# Game Boy release date, 1989-04-21T12:34:56Z (for reproducible test results)
+export SOURCE_DATE_EPOCH=609165296
+
+cd "$(dirname "$0")/.."
+
+RGBDS_PATH="RGBDS=../../"
+
+if [ ! -f "external/$1.cfg" ]; then
+	echo >&2 'External test file '"$1"'.cfg does not exist'
+	exit 1
+fi
+
+# Sourcing "external/$1.cfg" defines `EXTERNAL_TEST_*` values used below.
+. "external/$1.cfg"
+
+if ! cd "$EXTERNAL_TEST_REPO"; then
+	echo >&2 'Please fetch test deps before running any external test'
+	exit 1
+fi
+make clean $RGBDS_PATH
+make -j4 "$EXTERNAL_TEST_TARGET" $RGBDS_PATH
+hash="$(sha1sum -b "$EXTERNAL_TEST_FILE" | head -c 40)"
+if [ "$hash" != "$EXTERNAL_TEST_HASH" ]; then
+	cat >&2 <<EOM
+error: "$EXTERNAL_TEST_FILE" checksum did not match!
+    Expected $EXTERNAL_TEST_HASH,
+         got $hash
+EOM
+	exit 1
+fi

test/external/ucity.cfg

@@ -0,0 +1,7 @@
+EXTERNAL_TEST_OWNER=AntonioND
+EXTERNAL_TEST_REPO=ucity
+EXTERNAL_TEST_DOMAIN=github.com
+EXTERNAL_TEST_COMMIT=d1880a2a112d7c26f16c0fc06a15b6c32fdc9137
+EXTERNAL_TEST_TARGET=all
+EXTERNAL_TEST_FILE=ucity.gbc
+EXTERNAL_TEST_HASH=5f026649611c9606ce0bf70dc1552e054e7df5bc