new file mode 100644
--- /dev/null
+++ b/src/testing.c
@@ -0,0 +1,945 @@
+/* vi:set ts=8 sts=4 sw=4 noet:
+ *
+ * VIM - Vi IMproved	by Bram Moolenaar
+ *
+ * Do ":help uganda"  in Vim to read copying and usage conditions.
+ * Do ":help credits" in Vim to see a list of people who contributed.
+ * See README.txt for an overview of the Vim source code.
+ */
+
+/*
+ * testing.c: Support for tests.
+ */
+
+#include "vim.h"
+
+#if defined(FEAT_EVAL) || defined(PROTO)
+
+/*
+ * Prepare "gap" for an assert error and add the sourcing position.
+ */
+    static void
+prepare_assert_error(garray_T *gap)
+{
+    char buf[NUMBUFLEN];
+
+    ga_init2(gap, 1, 100);
+    if (sourcing_name != NULL)
+    {
+	ga_concat(gap, sourcing_name);
+	if (sourcing_lnum > 0)
+	    ga_concat(gap, (char_u *)" ");
+    }
+    if (sourcing_lnum > 0)
+    {
+	sprintf(buf, "line %ld", (long)sourcing_lnum);
+	ga_concat(gap, (char_u *)buf);
+    }
+    if (sourcing_name != NULL || sourcing_lnum > 0)
+	ga_concat(gap, (char_u *)": ");
+}
+
+/*
+ * Append "p[clen]" to "gap", escaping unprintable characters.
+ * Changes NL to \n, CR to \r, etc.
+ */
+    static void
+ga_concat_esc(garray_T *gap, char_u *p, int clen)
+{
+    char_u  buf[NUMBUFLEN];
+
+    if (clen > 1)
+    {
+	mch_memmove(buf, p, clen);
+	buf[clen] = NUL;
+	ga_concat(gap, buf);
+    }
+    else switch (*p)
+    {
+	case BS: ga_concat(gap, (char_u *)"\\b"); break;
+	case ESC: ga_concat(gap, (char_u *)"\\e"); break;
+	case FF: ga_concat(gap, (char_u *)"\\f"); break;
+	case NL: ga_concat(gap, (char_u *)"\\n"); break;
+	case TAB: ga_concat(gap, (char_u *)"\\t"); break;
+	case CAR: ga_concat(gap, (char_u *)"\\r"); break;
+	case '\\': ga_concat(gap, (char_u *)"\\\\"); break;
+	default:
+		   if (*p < ' ')
+		   {
+		       vim_snprintf((char *)buf, NUMBUFLEN, "\\x%02x", *p);
+		       ga_concat(gap, buf);
+		   }
+		   else
+		       ga_append(gap, *p);
+		   break;
+    }
+}
+
+/*
+ * Append "str" to "gap", escaping unprintable characters.
+ * Changes NL to \n, CR to \r, etc.
+ */
+    static void
+ga_concat_shorten_esc(garray_T *gap, char_u *str)
+{
+    char_u  *p;
+    char_u  *s;
+    int	    c;
+    int	    clen;
+    char_u  buf[NUMBUFLEN];
+    int	    same_len;
+
+    if (str == NULL)
+    {
+	ga_concat(gap, (char_u *)"NULL");
+	return;
+    }
+
+    for (p = str; *p != NUL; ++p)
+    {
+	same_len = 1;
+	s = p;
+	c = mb_ptr2char_adv(&s);
+	clen = s - p;
+	while (*s != NUL && c == mb_ptr2char(s))
+	{
+	    ++same_len;
+	    s += clen;
+	}
+	if (same_len > 20)
+	{
+	    ga_concat(gap, (char_u *)"\\[");
+	    ga_concat_esc(gap, p, clen);
+	    ga_concat(gap, (char_u *)" occurs ");
+	    vim_snprintf((char *)buf, NUMBUFLEN, "%d", same_len);
+	    ga_concat(gap, buf);
+	    ga_concat(gap, (char_u *)" times]");
+	    p = s - 1;
+	}
+	else
+	    ga_concat_esc(gap, p, clen);
+    }
+}
+
+/*
+ * Fill "gap" with information about an assert error.
+ */
+    static void
+fill_assert_error(
+    garray_T	*gap,
+    typval_T	*opt_msg_tv,
+    char_u      *exp_str,
+    typval_T	*exp_tv,
+    typval_T	*got_tv,
+    assert_type_T atype)
+{
+    char_u	numbuf[NUMBUFLEN];
+    char_u	*tofree;
+
+    if (opt_msg_tv->v_type != VAR_UNKNOWN)
+    {
+	ga_concat(gap, echo_string(opt_msg_tv, &tofree, numbuf, 0));
+	vim_free(tofree);
+	ga_concat(gap, (char_u *)": ");
+    }
+
+    if (atype == ASSERT_MATCH || atype == ASSERT_NOTMATCH)
+	ga_concat(gap, (char_u *)"Pattern ");
+    else if (atype == ASSERT_NOTEQUAL)
+	ga_concat(gap, (char_u *)"Expected not equal to ");
+    else
+	ga_concat(gap, (char_u *)"Expected ");
+    if (exp_str == NULL)
+    {
+	ga_concat_shorten_esc(gap, tv2string(exp_tv, &tofree, numbuf, 0));
+	vim_free(tofree);
+    }
+    else
+	ga_concat_shorten_esc(gap, exp_str);
+    if (atype != ASSERT_NOTEQUAL)
+    {
+	if (atype == ASSERT_MATCH)
+	    ga_concat(gap, (char_u *)" does not match ");
+	else if (atype == ASSERT_NOTMATCH)
+	    ga_concat(gap, (char_u *)" does match ");
+	else
+	    ga_concat(gap, (char_u *)" but got ");
+	ga_concat_shorten_esc(gap, tv2string(got_tv, &tofree, numbuf, 0));
+	vim_free(tofree);
+    }
+}
+
+    static int
+assert_equal_common(typval_T *argvars, assert_type_T atype)
+{
+    garray_T	ga;
+
+    if (tv_equal(&argvars[0], &argvars[1], FALSE, FALSE)
+						   != (atype == ASSERT_EQUAL))
+    {
+	prepare_assert_error(&ga);
+	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
+								       atype);
+	assert_error(&ga);
+	ga_clear(&ga);
+	return 1;
+    }
+    return 0;
+}
+
+    static int
+assert_match_common(typval_T *argvars, assert_type_T atype)
+{
+    garray_T	ga;
+    char_u	buf1[NUMBUFLEN];
+    char_u	buf2[NUMBUFLEN];
+    char_u	*pat = tv_get_string_buf_chk(&argvars[0], buf1);
+    char_u	*text = tv_get_string_buf_chk(&argvars[1], buf2);
+
+    if (pat == NULL || text == NULL)
+	emsg(_(e_invarg));
+    else if (pattern_match(pat, text, FALSE) != (atype == ASSERT_MATCH))
+    {
+	prepare_assert_error(&ga);
+	fill_assert_error(&ga, &argvars[2], NULL, &argvars[0], &argvars[1],
+									atype);
+	assert_error(&ga);
+	ga_clear(&ga);
+	return 1;
+    }
+    return 0;
+}
+
+/*
+ * Common for assert_true() and assert_false().
+ * Return non-zero for failure.
+ */
+    static int
+assert_bool(typval_T *argvars, int isTrue)
+{
+    int		error = FALSE;
+    garray_T	ga;
+
+    if (argvars[0].v_type == VAR_SPECIAL
+	    && argvars[0].vval.v_number == (isTrue ? VVAL_TRUE : VVAL_FALSE))
+	return 0;
+    if (argvars[0].v_type != VAR_NUMBER
+	    || (tv_get_number_chk(&argvars[0], &error) == 0) == isTrue
+	    || error)
+    {
+	prepare_assert_error(&ga);
+	fill_assert_error(&ga, &argvars[1],
+		(char_u *)(isTrue ? "True" : "False"),
+		NULL, &argvars[0], ASSERT_OTHER);
+	assert_error(&ga);
+	ga_clear(&ga);
+	return 1;
+    }
+    return 0;
+}
+
+    static void
+assert_append_cmd_or_arg(garray_T *gap, typval_T *argvars, char_u *cmd)
+{
+    char_u	*tofree;
+    char_u	numbuf[NUMBUFLEN];
+
+    if (argvars[1].v_type != VAR_UNKNOWN && argvars[2].v_type != VAR_UNKNOWN)
+    {
+	ga_concat(gap, echo_string(&argvars[2], &tofree, numbuf, 0));
+	vim_free(tofree);
+    }
+    else
+	ga_concat(gap, cmd);
+}
+
+    static int
+assert_beeps(typval_T *argvars)
+{
+    char_u	*cmd = tv_get_string_chk(&argvars[0]);
+    garray_T	ga;
+    int		ret = 0;
+
+    called_vim_beep = FALSE;
+    suppress_errthrow = TRUE;
+    emsg_silent = FALSE;
+    do_cmdline_cmd(cmd);
+    if (!called_vim_beep)
+    {
+	prepare_assert_error(&ga);
+	ga_concat(&ga, (char_u *)"command did not beep: ");
+	ga_concat(&ga, cmd);
+	assert_error(&ga);
+	ga_clear(&ga);
+	ret = 1;
+    }
+
+    suppress_errthrow = FALSE;
+    emsg_on_display = FALSE;
+    return ret;
+}
+
+/*
+ * "assert_beeps(cmd [, error])" function
+ */
+    void
+f_assert_beeps(typval_T *argvars, typval_T *rettv)
+{
+    rettv->vval.v_number = assert_beeps(argvars);
+}
+
+/*
+ * "assert_equal(expected, actual[, msg])" function
+ */
+    void
+f_assert_equal(typval_T *argvars, typval_T *rettv)
+{
+    rettv->vval.v_number = assert_equal_common(argvars, ASSERT_EQUAL);
+}
+
+    static int
+assert_equalfile(typval_T *argvars)
+{
+    char_u	buf1[NUMBUFLEN];
+    char_u	buf2[NUMBUFLEN];
+    char_u	*fname1 = tv_get_string_buf_chk(&argvars[0], buf1);
+    char_u	*fname2 = tv_get_string_buf_chk(&argvars[1], buf2);
+    garray_T	ga;
+    FILE	*fd1;
+    FILE	*fd2;
+
+    if (fname1 == NULL || fname2 == NULL)
+	return 0;
+
+    IObuff[0] = NUL;
+    fd1 = mch_fopen((char *)fname1, READBIN);
+    if (fd1 == NULL)
+    {
+	vim_snprintf((char *)IObuff, IOSIZE, (char *)e_notread, fname1);
+    }
+    else
+    {
+	fd2 = mch_fopen((char *)fname2, READBIN);
+	if (fd2 == NULL)
+	{
+	    fclose(fd1);
+	    vim_snprintf((char *)IObuff, IOSIZE, (char *)e_notread, fname2);
+	}
+	else
+	{
+	    int c1, c2;
+	    long count = 0;
+
+	    for (;;)
+	    {
+		c1 = fgetc(fd1);
+		c2 = fgetc(fd2);
+		if (c1 == EOF)
+		{
+		    if (c2 != EOF)
+			STRCPY(IObuff, "first file is shorter");
+		    break;
+		}
+		else if (c2 == EOF)
+		{
+		    STRCPY(IObuff, "second file is shorter");
+		    break;
+		}
+		else if (c1 != c2)
+		{
+		    vim_snprintf((char *)IObuff, IOSIZE,
+					      "difference at byte %ld", count);
+		    break;
+		}
+		++count;
+	    }
+	    fclose(fd1);
+	    fclose(fd2);
+	}
+    }
+    if (IObuff[0] != NUL)
+    {
+	prepare_assert_error(&ga);
+	ga_concat(&ga, IObuff);
+	assert_error(&ga);
+	ga_clear(&ga);
+	return 1;
+    }
+    return 0;
+}
+
+/*
+ * "assert_equalfile(fname-one, fname-two)" function
+ */
+    void
+f_assert_equalfile(typval_T *argvars, typval_T *rettv)
+{
+    rettv->vval.v_number = assert_equalfile(argvars);
+}
+
+/*
+ * "assert_notequal(expected, actual[, msg])" function
+ */
+    void
+f_assert_notequal(typval_T *argvars, typval_T *rettv)
+{
+    rettv->vval.v_number = assert_equal_common(argvars, ASSERT_NOTEQUAL);
+}
+
+/*
+ * "assert_exception(string[, msg])" function
+ */
+    void
+f_assert_exception(typval_T *argvars, typval_T *rettv)
+{
+    garray_T	ga;
+    char_u	*error = tv_get_string_chk(&argvars[0]);
+
+    if (*get_vim_var_str(VV_EXCEPTION) == NUL)
+    {
+	prepare_assert_error(&ga);
+	ga_concat(&ga, (char_u *)"v:exception is not set");
+	assert_error(&ga);
+	ga_clear(&ga);
+	rettv->vval.v_number = 1;
+    }
+    else if (error != NULL
+	&& strstr((char *)get_vim_var_str(VV_EXCEPTION), (char *)error) == NULL)
+    {
+	prepare_assert_error(&ga);
+	fill_assert_error(&ga, &argvars[1], NULL, &argvars[0],
+				  get_vim_var_tv(VV_EXCEPTION), ASSERT_OTHER);
+	assert_error(&ga);
+	ga_clear(&ga);
+	rettv->vval.v_number = 1;
+    }
+}
+
+/*
+ * "assert_fails(cmd [, error[, msg]])" function
+ */
+    void
+f_assert_fails(typval_T *argvars, typval_T *rettv)
+{
+    char_u	*cmd = tv_get_string_chk(&argvars[0]);
+    garray_T	ga;
+    int		save_trylevel = trylevel;
+
+    // trylevel must be zero for a ":throw" command to be considered failed
+    trylevel = 0;
+    called_emsg = FALSE;
+    suppress_errthrow = TRUE;
+    emsg_silent = TRUE;
+
+    do_cmdline_cmd(cmd);
+    if (!called_emsg)
+    {
+	prepare_assert_error(&ga);
+	ga_concat(&ga, (char_u *)"command did not fail: ");
+	assert_append_cmd_or_arg(&ga, argvars, cmd);
+	assert_error(&ga);
+	ga_clear(&ga);
+	rettv->vval.v_number = 1;
+    }
+    else if (argvars[1].v_type != VAR_UNKNOWN)
+    {
+	char_u	buf[NUMBUFLEN];
+	char	*error = (char *)tv_get_string_buf_chk(&argvars[1], buf);
+
+	if (error == NULL
+		  || strstr((char *)get_vim_var_str(VV_ERRMSG), error) == NULL)
+	{
+	    prepare_assert_error(&ga);
+	    fill_assert_error(&ga, &argvars[2], NULL, &argvars[1],
+				      get_vim_var_tv(VV_ERRMSG), ASSERT_OTHER);
+	    ga_concat(&ga, (char_u *)": ");
+	    assert_append_cmd_or_arg(&ga, argvars, cmd);
+	    assert_error(&ga);
+	    ga_clear(&ga);
+	    rettv->vval.v_number = 1;
+	}
+    }
+
+    trylevel = save_trylevel;
+    called_emsg = FALSE;
+    suppress_errthrow = FALSE;
+    emsg_silent = FALSE;
+    emsg_on_display = FALSE;
+    set_vim_var_string(VV_ERRMSG, NULL, 0);
+}
+
+/*
+ * "assert_false(actual[, msg])" function
+ */
+    void
+f_assert_false(typval_T *argvars, typval_T *rettv)
+{
+    rettv->vval.v_number = assert_bool(argvars, FALSE);
+}
+
+    static int
+assert_inrange(typval_T *argvars)
+{
+    garray_T	ga;
+    int		error = FALSE;
+    char_u	*tofree;
+    char	msg[200];
+    char_u	numbuf[NUMBUFLEN];
+
+#ifdef FEAT_FLOAT
+    if (argvars[0].v_type == VAR_FLOAT
+	    || argvars[1].v_type == VAR_FLOAT
+	    || argvars[2].v_type == VAR_FLOAT)
+    {
+	float_T flower = tv_get_float(&argvars[0]);
+	float_T fupper = tv_get_float(&argvars[1]);
+	float_T factual = tv_get_float(&argvars[2]);
+
+	if (factual < flower || factual > fupper)
+	{
+	    prepare_assert_error(&ga);
+	    if (argvars[3].v_type != VAR_UNKNOWN)
+	    {
+		ga_concat(&ga, tv2string(&argvars[3], &tofree, numbuf, 0));
+		vim_free(tofree);
+	    }
+	    else
+	    {
+		vim_snprintf(msg, 200, "Expected range %g - %g, but got %g",
+						      flower, fupper, factual);
+		ga_concat(&ga, (char_u *)msg);
+	    }
+	    assert_error(&ga);
+	    ga_clear(&ga);
+	    return 1;
+	}
+    }
+    else
+#endif
+    {
+	varnumber_T	lower = tv_get_number_chk(&argvars[0], &error);
+	varnumber_T	upper = tv_get_number_chk(&argvars[1], &error);
+	varnumber_T	actual = tv_get_number_chk(&argvars[2], &error);
+
+	if (error)
+	    return 0;
+	if (actual < lower || actual > upper)
+	{
+	    prepare_assert_error(&ga);
+	    if (argvars[3].v_type != VAR_UNKNOWN)
+	    {
+		ga_concat(&ga, tv2string(&argvars[3], &tofree, numbuf, 0));
+		vim_free(tofree);
+	    }
+	    else
+	    {
+		vim_snprintf(msg, 200, "Expected range %ld - %ld, but got %ld",
+				       (long)lower, (long)upper, (long)actual);
+		ga_concat(&ga, (char_u *)msg);
+	    }
+	    assert_error(&ga);
+	    ga_clear(&ga);
+	    return 1;
+	}
+    }
+    return 0;
+}
+
+/*
+ * "assert_inrange(lower, upper[, msg])" function
+ */
+    void
+f_assert_inrange(typval_T *argvars, typval_T *rettv)
+{
+    rettv->vval.v_number = assert_inrange(argvars);
+}
+
+/*
+ * "assert_match(pattern, actual[, msg])" function
+ */
+    void
+f_assert_match(typval_T *argvars, typval_T *rettv)
+{
+    rettv->vval.v_number = assert_match_common(argvars, ASSERT_MATCH);
+}
+
+/*
+ * "assert_notmatch(pattern, actual[, msg])" function
+ */
+    void
+f_assert_notmatch(typval_T *argvars, typval_T *rettv)
+{
+    rettv->vval.v_number = assert_match_common(argvars, ASSERT_NOTMATCH);
+}
+
+/*
+ * "assert_report(msg)" function
+ */
+    void
+f_assert_report(typval_T *argvars, typval_T *rettv)
+{
+    garray_T	ga;
+
+    prepare_assert_error(&ga);
+    ga_concat(&ga, tv_get_string(&argvars[0]));
+    assert_error(&ga);
+    ga_clear(&ga);
+    rettv->vval.v_number = 1;
+}
+
+/*
+ * "assert_true(actual[, msg])" function
+ */
+    void
+f_assert_true(typval_T *argvars, typval_T *rettv)
+{
+    rettv->vval.v_number = assert_bool(argvars, TRUE);
+}
+
+/*
+ * "test_alloc_fail(id, countdown, repeat)" function
+ */
+    void
+f_test_alloc_fail(typval_T *argvars, typval_T *rettv UNUSED)
+{
+    if (argvars[0].v_type != VAR_NUMBER
+	    || argvars[0].vval.v_number <= 0
+	    || argvars[1].v_type != VAR_NUMBER
+	    || argvars[1].vval.v_number < 0
+	    || argvars[2].v_type != VAR_NUMBER)
+	emsg(_(e_invarg));
+    else
+    {
+	alloc_fail_id = argvars[0].vval.v_number;
+	if (alloc_fail_id >= aid_last)
+	    emsg(_(e_invarg));
+	alloc_fail_countdown = argvars[1].vval.v_number;
+	alloc_fail_repeat = argvars[2].vval.v_number;
+	did_outofmem_msg = FALSE;
+    }
+}
+
+/*
+ * "test_autochdir()"
+ */
+    void
+f_test_autochdir(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
+{
+#if defined(FEAT_AUTOCHDIR)
+    test_autochdir = TRUE;
+#endif
+}
+
+/*
+ * "test_feedinput()"
+ */
+    void
+f_test_feedinput(typval_T *argvars, typval_T *rettv UNUSED)
+{
+#ifdef USE_INPUT_BUF
+    char_u	*val = tv_get_string_chk(&argvars[0]);
+
+    if (val != NULL)
+    {
+	trash_input_buf();
+	add_to_input_buf_csi(val, (int)STRLEN(val));
+    }
+#endif
+}
+
+/*
+ * "test_getvalue({name})" function
+ */
+    void
+f_test_getvalue(typval_T *argvars, typval_T *rettv)
+{
+    if (argvars[0].v_type != VAR_STRING)
+	emsg(_(e_invarg));
+    else
+    {
+	char_u *name = tv_get_string(&argvars[0]);
+
+	if (STRCMP(name, (char_u *)"need_fileinfo") == 0)
+	    rettv->vval.v_number = need_fileinfo;
+	else
+	    semsg(_(e_invarg2), name);
+    }
+}
+
+/*
+ * "test_option_not_set({name})" function
+ */
+    void
+f_test_option_not_set(typval_T *argvars, typval_T *rettv UNUSED)
+{
+    char_u *name = (char_u *)"";
+
+    if (argvars[0].v_type != VAR_STRING)
+	emsg(_(e_invarg));
+    else
+    {
+	name = tv_get_string(&argvars[0]);
+	if (reset_option_was_set(name) == FAIL)
+	    semsg(_(e_invarg2), name);
+    }
+}
+
+/*
+ * "test_override({name}, {val})" function
+ */
+    void
+f_test_override(typval_T *argvars, typval_T *rettv UNUSED)
+{
+    char_u *name = (char_u *)"";
+    int     val;
+    static int save_starting = -1;
+
+    if (argvars[0].v_type != VAR_STRING
+	    || (argvars[1].v_type) != VAR_NUMBER)
+	emsg(_(e_invarg));
+    else
+    {
+	name = tv_get_string(&argvars[0]);
+	val = (int)tv_get_number(&argvars[1]);
+
+	if (STRCMP(name, (char_u *)"redraw") == 0)
+	    disable_redraw_for_testing = val;
+	else if (STRCMP(name, (char_u *)"redraw_flag") == 0)
+	    ignore_redraw_flag_for_testing = val;
+	else if (STRCMP(name, (char_u *)"char_avail") == 0)
+	    disable_char_avail_for_testing = val;
+	else if (STRCMP(name, (char_u *)"starting") == 0)
+	{
+	    if (val)
+	    {
+		if (save_starting < 0)
+		    save_starting = starting;
+		starting = 0;
+	    }
+	    else
+	    {
+		starting = save_starting;
+		save_starting = -1;
+	    }
+	}
+	else if (STRCMP(name, (char_u *)"nfa_fail") == 0)
+	    nfa_fail_for_testing = val;
+	else if (STRCMP(name, (char_u *)"no_query_mouse") == 0)
+	    no_query_mouse_for_testing = val;
+	else if (STRCMP(name, (char_u *)"no_wait_return") == 0)
+	    no_wait_return = val;
+	else if (STRCMP(name, (char_u *)"ALL") == 0)
+	{
+	    disable_char_avail_for_testing = FALSE;
+	    disable_redraw_for_testing = FALSE;
+	    ignore_redraw_flag_for_testing = FALSE;
+	    nfa_fail_for_testing = FALSE;
+	    no_query_mouse_for_testing = FALSE;
+	    if (save_starting >= 0)
+	    {
+		starting = save_starting;
+		save_starting = -1;
+	    }
+	}
+	else
+	    semsg(_(e_invarg2), name);
+    }
+}
+
+/*
+ * "test_refcount({expr})" function
+ */
+    void
+f_test_refcount(typval_T *argvars, typval_T *rettv)
+{
+    int retval = -1;
+
+    switch (argvars[0].v_type)
+    {
+	case VAR_UNKNOWN:
+	case VAR_NUMBER:
+	case VAR_FLOAT:
+	case VAR_SPECIAL:
+	case VAR_STRING:
+	    break;
+	case VAR_JOB:
+#ifdef FEAT_JOB_CHANNEL
+	    if (argvars[0].vval.v_job != NULL)
+		retval = argvars[0].vval.v_job->jv_refcount - 1;
+#endif
+	    break;
+	case VAR_CHANNEL:
+#ifdef FEAT_JOB_CHANNEL
+	    if (argvars[0].vval.v_channel != NULL)
+		retval = argvars[0].vval.v_channel->ch_refcount - 1;
+#endif
+	    break;
+	case VAR_FUNC:
+	    if (argvars[0].vval.v_string != NULL)
+	    {
+		ufunc_T *fp;
+
+		fp = find_func(argvars[0].vval.v_string);
+		if (fp != NULL)
+		    retval = fp->uf_refcount;
+	    }
+	    break;
+	case VAR_PARTIAL:
+	    if (argvars[0].vval.v_partial != NULL)
+		retval = argvars[0].vval.v_partial->pt_refcount - 1;
+	    break;
+	case VAR_BLOB:
+	    if (argvars[0].vval.v_blob != NULL)
+		retval = argvars[0].vval.v_blob->bv_refcount - 1;
+	    break;
+	case VAR_LIST:
+	    if (argvars[0].vval.v_list != NULL)
+		retval = argvars[0].vval.v_list->lv_refcount - 1;
+	    break;
+	case VAR_DICT:
+	    if (argvars[0].vval.v_dict != NULL)
+		retval = argvars[0].vval.v_dict->dv_refcount - 1;
+	    break;
+    }
+
+    rettv->v_type = VAR_NUMBER;
+    rettv->vval.v_number = retval;
+
+}
+
+/*
+ * "test_garbagecollect_now()" function
+ */
+    void
+f_test_garbagecollect_now(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
+{
+    /* This is dangerous, any Lists and Dicts used internally may be freed
+     * while still in use. */
+    garbage_collect(TRUE);
+}
+
+/*
+ * "test_garbagecollect_soon()" function
+ */
+    void
+f_test_garbagecollect_soon(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
+{
+    may_garbage_collect = TRUE;
+}
+
+/*
+ * "test_ignore_error()" function
+ */
+    void
+f_test_ignore_error(typval_T *argvars, typval_T *rettv UNUSED)
+{
+     ignore_error_for_testing(tv_get_string(&argvars[0]));
+}
+
+    void
+f_test_null_blob(typval_T *argvars UNUSED, typval_T *rettv)
+{
+    rettv->v_type = VAR_BLOB;
+    rettv->vval.v_blob = NULL;
+}
+
+#ifdef FEAT_JOB_CHANNEL
+    void
+f_test_null_channel(typval_T *argvars UNUSED, typval_T *rettv)
+{
+    rettv->v_type = VAR_CHANNEL;
+    rettv->vval.v_channel = NULL;
+}
+#endif
+
+    void
+f_test_null_dict(typval_T *argvars UNUSED, typval_T *rettv)
+{
+    rettv_dict_set(rettv, NULL);
+}
+
+#ifdef FEAT_JOB_CHANNEL
+    void
+f_test_null_job(typval_T *argvars UNUSED, typval_T *rettv)
+{
+    rettv->v_type = VAR_JOB;
+    rettv->vval.v_job = NULL;
+}
+#endif
+
+    void
+f_test_null_list(typval_T *argvars UNUSED, typval_T *rettv)
+{
+    rettv_list_set(rettv, NULL);
+}
+
+    void
+f_test_null_partial(typval_T *argvars UNUSED, typval_T *rettv)
+{
+    rettv->v_type = VAR_PARTIAL;
+    rettv->vval.v_partial = NULL;
+}
+
+    void
+f_test_null_string(typval_T *argvars UNUSED, typval_T *rettv)
+{
+    rettv->v_type = VAR_STRING;
+    rettv->vval.v_string = NULL;
+}
+
+#ifdef FEAT_GUI
+    void
+f_test_scrollbar(typval_T *argvars, typval_T *rettv UNUSED)
+{
+    char_u	*which;
+    long	value;
+    int		dragging;
+    scrollbar_T *sb = NULL;
+
+    if (argvars[0].v_type != VAR_STRING
+	    || (argvars[1].v_type) != VAR_NUMBER
+	    || (argvars[2].v_type) != VAR_NUMBER)
+    {
+	emsg(_(e_invarg));
+	return;
+    }
+    which = tv_get_string(&argvars[0]);
+    value = tv_get_number(&argvars[1]);
+    dragging = tv_get_number(&argvars[2]);
+
+    if (STRCMP(which, "left") == 0)
+	sb = &curwin->w_scrollbars[SBAR_LEFT];
+    else if (STRCMP(which, "right") == 0)
+	sb = &curwin->w_scrollbars[SBAR_RIGHT];
+    else if (STRCMP(which, "hor") == 0)
+	sb = &gui.bottom_sbar;
+    if (sb == NULL)
+    {
+	semsg(_(e_invarg2), which);
+	return;
+    }
+    gui_drag_scrollbar(sb, value, dragging);
+# ifndef USE_ON_FLY_SCROLL
+    // need to loop through normal_cmd() to handle the scroll events
+    exec_normal(FALSE, TRUE, FALSE);
+# endif
+}
+#endif
+
+#ifdef FEAT_MOUSE
+    void
+f_test_setmouse(typval_T *argvars, typval_T *rettv UNUSED)
+{
+    mouse_row = (time_t)tv_get_number(&argvars[0]) - 1;
+    mouse_col = (time_t)tv_get_number(&argvars[1]) - 1;
+}
+#endif
+
+    void
+f_test_settime(typval_T *argvars, typval_T *rettv UNUSED)
+{
+    time_for_testing = (time_t)tv_get_number(&argvars[0]);
+}
+
+
+#endif // defined(FEAT_EVAL)