diff --git a/tools/rbcrun/testdata/cli_and_env.star b/tools/rbcrun/testdata/cli_and_env.star
new file mode 100644
index 0000000..d6f464a
--- /dev/null
+++ b/tools/rbcrun/testdata/cli_and_env.star
@@ -0,0 +1,11 @@
+# Tests rblf_env access
+load("assert.star", "assert")
+
+
+def test():
+    assert.eq(rblf_env.TEST_ENVIRONMENT_FOO, "test_environment_foo")
+    assert.fails(lambda: rblf_env.FOO_BAR_BAZ, ".*struct has no .FOO_BAR_BAZ attribute$")
+    assert.eq(rblf_cli.CLI_FOO, "foo")
+
+
+test()
diff --git a/tools/rbcrun/testdata/file_ops.star b/tools/rbcrun/testdata/file_ops.star
new file mode 100644
index 0000000..e1f1ac2
--- /dev/null
+++ b/tools/rbcrun/testdata/file_ops.star
@@ -0,0 +1,18 @@
+# Tests file ops builtins
+load("assert.star", "assert")
+
+
+def test():
+    myname = "file_ops.star"
+    assert.true(rblf_file_exists(myname), "the file %s does exist" % myname)
+    assert.true(not rblf_file_exists("no_such_file"), "the file no_such_file does not exist")
+    files = rblf_wildcard("*.star")
+    assert.true(myname in files, "expected %s in  %s" % (myname, files))
+    # RBCDATADIR is set by the caller to the path where this file resides
+    files = rblf_wildcard("*.star", rblf_env.TEST_DATA_DIR)
+    assert.true(myname in files, "expected %s in %s" % (myname, files))
+    files = rblf_wildcard("*.xxx")
+    assert.true(len(files) == 0, "expansion should be empty but contains %s" % files)
+
+
+test()
diff --git a/tools/rbcrun/testdata/load.star b/tools/rbcrun/testdata/load.star
new file mode 100644
index 0000000..b14f2bb
--- /dev/null
+++ b/tools/rbcrun/testdata/load.star
@@ -0,0 +1,14 @@
+# Test load, simple and conditional
+load("assert.star", "assert")
+load(":module1.star", test1="test")
+load("//testdata:module2.star", test2="test")
+load(":module3|test", test3="test")
+
+
+def test():
+    assert.eq(test1, "module1")
+    assert.eq(test2, "module2")
+    assert.eq(test3, None)
+
+
+test()
diff --git a/tools/rbcrun/testdata/module1.star b/tools/rbcrun/testdata/module1.star
new file mode 100644
index 0000000..913fb7d
--- /dev/null
+++ b/tools/rbcrun/testdata/module1.star
@@ -0,0 +1,7 @@
+# Module loaded my load.star
+load("assert.star", "assert")
+
+# Make sure that builtins are defined for the loaded module, too
+assert.true(rblf_file_exists("module1.star"))
+assert.true(not rblf_file_exists("no_such file"))
+test = "module1"
diff --git a/tools/rbcrun/testdata/module2.star b/tools/rbcrun/testdata/module2.star
new file mode 100644
index 0000000..f6818a2
--- /dev/null
+++ b/tools/rbcrun/testdata/module2.star
@@ -0,0 +1,2 @@
+# Module loaded my load.star
+test = "module2"
diff --git a/tools/rbcrun/testdata/regex.star b/tools/rbcrun/testdata/regex.star
new file mode 100644
index 0000000..04e1d42
--- /dev/null
+++ b/tools/rbcrun/testdata/regex.star
@@ -0,0 +1,13 @@
+# Tests rblf_regex
+load("assert.star", "assert")
+
+
+def test():
+    pattern = "^(foo.*bar|abc.*d|1.*)$"
+    for w in ("foobar", "fooxbar", "abcxd", "123"):
+        assert.true(rblf_regex(pattern, w), "%s should match %s" % (w, pattern))
+    for w in ("afoobar", "abcde"):
+        assert.true(not rblf_regex(pattern, w), "%s should not match %s" % (w, pattern))
+
+
+test()
diff --git a/tools/rbcrun/testdata/shell.star b/tools/rbcrun/testdata/shell.star
new file mode 100644
index 0000000..ad10697
--- /dev/null
+++ b/tools/rbcrun/testdata/shell.star
@@ -0,0 +1,5 @@
+# Tests "queue" data type
+load("assert.star", "assert")
+
+assert.eq("load.star shell.star", rblf_shell("cd %s && ls -1 shell.star load.star 2>&1" % rblf_env.TEST_DATA_DIR))
+assert.eq("shell.star", rblf_shell("cd %s && echo shell.sta*" % rblf_env.TEST_DATA_DIR))