tests: Avoid bogus error message during test runs

The distcheck unit test caused remote network traffic, which is bad from
a testing perspective. Additionally, it printed error messages to
stderr.

Avoid both of these problems by replacing the curl command with a mock
for the time of the test. This will also speed up the test.

Drop the unit test for the filesize distcheck.type, since there is no
good way to actually test whether it succeeds.

Closes: https://trac.macports.org/ticket/52218

src/port1.0/tests/portdistcheck.test

@@ -18,9 +18,7 @@ source ./library.tcl
 macports_worker_init
 
 
-test distcheck_main {
-    Distcheck main unit test.
-} -setup {
+set distcheck_fixture_setup {
     set portpath $pwd
     set filespath $pwd/files
 
@@ -34,20 +32,40 @@ test distcheck_main {
     set porturl "http://distfiles.macports.org/gcc_select/"
     set master_sites $porturl
     set extract.suffix .tar.gz
-
-} -body {
     set fetch.type standard
-    set distcheck.type moddate
-    if {[portdistcheck::distcheck_main] != ""} {
-        return "FAIL: unable to download or check file, type moddate"
-    }
-    set distcheck.type filesize
-    if {[portdistcheck::distcheck_main] != ""} {
-        return "FAIL: unable to download or check file, type filesize"
+
+    # replace curl with a mock
+    rename curl _save_curl
+    proc curl {operation args} {
+        global _test_isnewer
+        switch $operation {
+            isnewer {
+                return ${_test_isnewer}
+            }
+        }
     }
+}
+set distcheck_fixture_cleanup {
+    # restore original curl
+    rename curl ""
+    rename _save_curl curl
+}
 
-    return "Distcheck main successful."
-} -result "Distcheck main successful."
+test distcheck_moddate_newer {
+    Check that files on servers that are newer than the Portfile cause a warning.
+} -setup $distcheck_fixture_setup -cleanup $distcheck_fixture_cleanup -body {
+    set distcheck.type moddate
+    set _test_isnewer 1
+    return [portdistcheck::distcheck_main]
+} -errorOutput "Warning: port gcc_select: .* is newer than Portfile" -match regexp
+
+test distcheck_moddate_not_newer {
+    Check that files on server that are not newer than the Portfile do not cause a warning
+} -setup $distcheck_fixture_setup -cleanup $distcheck_fixture_cleanup -body {
+    set distcheck.type moddate
+    set _test_isnewer 0
+    return [portdistcheck::distcheck_main]
+} -errorOutput ""
 
 
 cleanupTests