Add a build system for the junit tests.

This is a bit more complicated than our usual setup, as we both need to
unzip the typescript parser wrapper, and make node accessible on the path.

javascript/extractor/test/com/semmle/js/extractor/test/AutoBuildTests.java

@@ -30,6 +30,7 @@ import com.semmle.js.extractor.FileExtractor;
 import com.semmle.js.extractor.FileExtractor.FileType;
 import com.semmle.js.extractor.VirtualSourceRoot;
 import com.semmle.util.data.StringUtil;
+import com.semmle.util.exception.Exceptions;
 import com.semmle.util.exception.UserError;
 import com.semmle.util.files.FileUtil;
 import com.semmle.util.files.FileUtil8;
@@ -443,8 +444,12 @@ public class AutoBuildTests {
 
   /** Hide {@code p} on using {@link DosFileAttributeView} if available; otherwise do nothing. */
   private void hide(Path p) throws IOException {
+    try {
     DosFileAttributeView attrs = Files.getFileAttributeView(p, DosFileAttributeView.class);
     if (attrs != null) attrs.setHidden(true);
+    } catch (IOException e) {
+      Exceptions.ignore(e, "On Linux within the bazel sandbox, we get a DosFileAttributeView that then throws an exception upon use");
+    }
   }
 
   @Test

javascript/extractor/test/com/semmle/js/extractor/test/BUILD.bazel

@@ -0,0 +1,33 @@
+java_test(
+    name = "test_jar",
+    srcs = glob(["**/*.java"]),
+    test_class = "com.semmle.js.extractor.test.AllTests",
+    deps = [
+        "//javascript/extractor",
+        "//javascript/extractor:deps",
+        "@//resources/lib/java/DO_NOT_DISTRIBUTE:junit",
+    ],
+)
+
+# We need to unzip the typescript wrapper, and provide node on the path.
+# Therefore, we're wrapping the java_test inside a sh_test.
+sh_test(
+    name = "test",
+    size = "small",
+    srcs = ["run_tests.sh"],
+    args = [
+        "$(execpath @nodejs//:node_bin)",
+        "$(JAVABASE)/bin/java",
+        "$(rootpath //javascript/extractor/lib/typescript)",
+        "$(rootpath test_jar_deploy.jar)",
+    ],
+    data = [
+        ":test_jar_deploy.jar",
+        "//javascript/extractor/lib/typescript",
+        "//javascript/extractor/parser-tests",
+        "//javascript/extractor/tests",
+        "@bazel_tools//tools/jdk:current_java_runtime",
+        "@nodejs//:node_bin",
+    ],
+    toolchains = ["@bazel_tools//tools/jdk:current_java_runtime"],
+)

javascript/extractor/test/com/semmle/js/extractor/test/run_tests.sh

@@ -0,0 +1,31 @@
+NODE=$1
+JAVA=$2
+PARSER_WRAPPER=$3
+TEST_JAR=$4
+
+TEMP=$(mktemp -d)
+
+UNAME=$(uname -s)
+echo $UNAME
+# On Windows, the symlink set up by bazel that points at the test jar is a msys2/linux-style path
+# The JVM can't resolve that, therefore copy the jar to the temp directory, and then set the
+# windows path to it
+if [[ "$UNAME" =~ _NT ]]; then
+    cp $TEST_JAR $TEMP/test.jar
+    TEST_JAR=$(cygpath -w $TEMP/test.jar)
+    echo "On Windows, new test jar: $TEST_JAR"
+fi
+
+# unpack parser wrapper
+unzip -q $PARSER_WRAPPER -d $TEMP/parser_wrapper
+export SEMMLE_TYPESCRIPT_PARSER_WRAPPER=$TEMP/parser_wrapper/javascript/tools/typescript-parser-wrapper/main.js
+
+# setup node on path
+NODE=$(realpath $NODE)
+export PATH="$PATH:$(dirname $NODE)"
+
+$JAVA -Dbazel.test_suite=com.semmle.js.extractor.test.AllTests -jar $TEST_JAR
+EXIT_CODE=$?
+
+rm -rf $TEMP
+exit $EXIT_CODE