diff --git a/.gitignore b/.gitignore
index 5a0ab4a2..4cfd7cae 100644
--- a/.gitignore
+++ b/.gitignore
@@ -29,6 +29,7 @@ Makefile.in
 /tests/.git*
 /tests/.hg*
 /tests/nix
+/tests/data
 /inst
 hydra-config.h
 hydra-config.h.in
diff --git a/tests/input-types.t b/tests/input-types.t
deleted file mode 100644
index bda15b96..00000000
--- a/tests/input-types.t
+++ /dev/null
@@ -1,122 +0,0 @@
-use strict;
-use Cwd;
-use Setup;
-
-(my $datadir, my $pgsql) = test_init();
-
-require Hydra::Schema;
-require Hydra::Model::DB;
-
-use Test2::V0;
-
-my $db = Hydra::Model::DB->new;
-hydra_setup($db);
-
-my $testdir = getcwd;
-my $scratchdir = "$datadir/scratch";
-mkdir $scratchdir;
-my $jobsBaseUri = "file://".$scratchdir;
-
-# Test scm inputs
-my @scminputs = (
-    {
-        name => "svn",
-        nixexpr => "svn-input.nix",
-        type => "svn",
-        uri => "$jobsBaseUri/svn-repo",
-        update => $testdir . "/jobs/svn-update.sh"
-    },
-    {
-        name => "svn-checkout",
-        nixexpr => "svn-checkout-input.nix",
-        type => "svn-checkout",
-        uri => "$jobsBaseUri/svn-checkout-repo",
-        update => $testdir . "/jobs/svn-checkout-update.sh"
-    },
-    {
-        name => "git",
-        nixexpr => "git-input.nix",
-        type => "git",
-        uri => "$jobsBaseUri/git-repo",
-        update => $testdir . "/jobs/git-update.sh"
-    },
-    {
-        name => "git-rev",
-        nixexpr => "git-rev-input.nix",
-        type => "git",
-        uri => "$jobsBaseUri/git-repo 7f60df502b96fd54bbfa64dd94b56d936a407701",
-        update => $testdir . "/jobs/git-rev-update.sh"
-    },
-    {
-        name => "deepgit",
-        nixexpr => "deepgit-input.nix",
-        type => "git",
-        uri => "$jobsBaseUri/git-repo master 1",
-        update => $testdir . "/jobs/git-update.sh"
-    },
-    {
-        name => "bzr",
-        nixexpr => "bzr-input.nix",
-        type => "bzr",
-        uri => "$jobsBaseUri/bzr-repo",
-        update => $testdir . "/jobs/bzr-update.sh"
-    },
-    {
-        name => "bzr-checkout",
-        nixexpr => "bzr-checkout-input.nix",
-        type => "bzr-checkout",
-        uri => "$jobsBaseUri/bzr-checkout-repo",
-        update => $testdir . "/jobs/bzr-checkout-update.sh"
-    },
-    {
-        name => "hg",
-        nixexpr => "hg-input.nix",
-        type => "hg",
-        uri => "$jobsBaseUri/hg-repo",
-        update => $testdir . "/jobs/hg-update.sh"
-    },
-    {
-        name => "darcs",
-        nixexpr => "darcs-input.nix",
-        type => "darcs",
-        uri => "$jobsBaseUri/darcs-repo",
-        update => $testdir . "/jobs/darcs-update.sh"
-    }
-);
-
-foreach my $scm ( @scminputs ) {
-    my $scmName = $scm->{"name"};
-
-    subtest "With the SCM input named $scmName" => sub {
-        my $nixexpr = $scm->{"nixexpr"};
-        my $type = $scm->{"type"};
-        my $uri = $scm->{"uri"};
-        my $update = $scm->{"update"};
-        my $jobset = createJobsetWithOneInput($scmName, $nixexpr, "src", $type, $uri);
-
-        my $state = 0;
-        my $q = 0;
-        my ($loop, $updated) = updateRepository($scmName, $update, $scratchdir);
-        while($loop) {
-            subtest "Mutation number $state" => sub {
-                # Verify that it can be fetched and possibly queued.
-                ok(evalSucceeds($jobset),                  "Evaluating nix-expression.");
-
-                # Verify that the evaluation has queued a new job and evaluate again to ...
-                if ($updated) {
-                    $q++;
-                    is(nrQueuedBuildsForJobset($jobset), $q, "Expect $q jobs in the queue.");
-                    ok(evalSucceeds($jobset),                "Evaluating nix-expression again.");
-                }
-
-                # ... check that it is deterministic and not queued again.
-                is(nrQueuedBuildsForJobset($jobset), $q, "Expect deterministic evaluation.");
-
-                $state++;
-                ($loop, $updated) = updateRepository($scmName, $update, $scratchdir);
-            };
-        }
-    };
-}
-
-done_testing;
diff --git a/tests/input-types/bzr-checkout.t b/tests/input-types/bzr-checkout.t
new file mode 100644
index 00000000..2bcf556f
--- /dev/null
+++ b/tests/input-types/bzr-checkout.t
@@ -0,0 +1,28 @@
+use strict;
+use Cwd;
+use Setup;
+use TestScmInput;
+
+(my $datadir, my $pgsql) = test_init();
+
+require Hydra::Schema;
+require Hydra::Model::DB;
+
+use Test2::V0;
+
+my $db = Hydra::Model::DB->new;
+hydra_setup($db);
+
+# Tests the creation of a Hydra jobset using a bzr checkout as input.
+testScmInput(
+  type => 'bzr-checkout',
+  expr => 'bzr-checkout-input.nix',
+  uri => 'bzr-checkout-repo',
+  update => 'jobs/bzr-checkout-update.sh',
+
+  # directories
+  datadir => $datadir,
+  testdir => getcwd,
+);
+
+done_testing;
diff --git a/tests/input-types/bzr.t b/tests/input-types/bzr.t
new file mode 100644
index 00000000..345f5aca
--- /dev/null
+++ b/tests/input-types/bzr.t
@@ -0,0 +1,28 @@
+use strict;
+use Cwd;
+use Setup;
+use TestScmInput;
+
+(my $datadir, my $pgsql) = test_init();
+
+require Hydra::Schema;
+require Hydra::Model::DB;
+
+use Test2::V0;
+
+my $db = Hydra::Model::DB->new;
+hydra_setup($db);
+
+# Tests the creation of a Hydra jobset using a bzr repo as input.
+testScmInput(
+  type => 'bzr',
+  expr => 'bzr-input.nix',
+  uri => 'bzr-repo',
+  update => 'jobs/bzr-update.sh',
+
+  # directories
+  datadir => $datadir,
+  testdir => getcwd,
+);
+
+done_testing;
diff --git a/tests/input-types/darcs.t b/tests/input-types/darcs.t
new file mode 100644
index 00000000..afbbd630
--- /dev/null
+++ b/tests/input-types/darcs.t
@@ -0,0 +1,28 @@
+use strict;
+use Cwd;
+use Setup;
+use TestScmInput;
+
+(my $datadir, my $pgsql) = test_init();
+
+require Hydra::Schema;
+require Hydra::Model::DB;
+
+use Test2::V0;
+
+my $db = Hydra::Model::DB->new;
+hydra_setup($db);
+
+# Tests the creation of a Hydra jobset using a darcs repo as input.
+testScmInput(
+  type => 'darcs',
+  expr => 'darcs-input.nix',
+  uri => 'darcs-repo',
+  update => 'jobs/darcs-update.sh',
+
+  # directories
+  datadir => $datadir,
+  testdir => getcwd,
+);
+
+done_testing;
diff --git a/tests/input-types/deepgit.t b/tests/input-types/deepgit.t
new file mode 100644
index 00000000..7db0e2ce
--- /dev/null
+++ b/tests/input-types/deepgit.t
@@ -0,0 +1,29 @@
+use strict;
+use Cwd;
+use Setup;
+use TestScmInput;
+
+(my $datadir, my $pgsql) = test_init();
+
+require Hydra::Schema;
+require Hydra::Model::DB;
+
+use Test2::V0;
+
+my $db = Hydra::Model::DB->new;
+hydra_setup($db);
+
+# Tests the creation of a Hydra jobset using a deep git clone as input.
+testScmInput(
+  type => 'git',
+  name => 'deepgit',
+  expr => 'deepgit-input.nix',
+  uri => 'git-repo master 1',
+  update => 'jobs/git-update.sh',
+
+  # directories
+  datadir => $datadir,
+  testdir => getcwd,
+);
+
+done_testing;
diff --git a/tests/input-types/git-rev.t b/tests/input-types/git-rev.t
new file mode 100644
index 00000000..58d23a99
--- /dev/null
+++ b/tests/input-types/git-rev.t
@@ -0,0 +1,29 @@
+use strict;
+use Cwd;
+use Setup;
+use TestScmInput;
+
+(my $datadir, my $pgsql) = test_init();
+
+require Hydra::Schema;
+require Hydra::Model::DB;
+
+use Test2::V0;
+
+my $db = Hydra::Model::DB->new;
+hydra_setup($db);
+
+# Tests the creation of a Hydra jobset using a git revision as input.
+testScmInput(
+  type => 'git',
+  name => 'git-rev',
+  expr => 'git-rev-input.nix',
+  uri => 'git-repo 7f60df502b96fd54bbfa64dd94b56d936a407701',
+  update => 'jobs/git-rev-update.sh',
+
+  # directories
+  datadir => $datadir,
+  testdir => getcwd,
+);
+
+done_testing;
diff --git a/tests/input-types/git.t b/tests/input-types/git.t
new file mode 100644
index 00000000..82eafa97
--- /dev/null
+++ b/tests/input-types/git.t
@@ -0,0 +1,28 @@
+use strict;
+use Cwd;
+use Setup;
+use TestScmInput;
+
+(my $datadir, my $pgsql) = test_init();
+
+require Hydra::Schema;
+require Hydra::Model::DB;
+
+use Test2::V0;
+
+my $db = Hydra::Model::DB->new;
+hydra_setup($db);
+
+# Tests the creation of a Hydra jobset using a git repo as input.
+testScmInput(
+  type => 'git',
+  expr => 'git-input.nix',
+  uri => 'git-repo',
+  update => 'jobs/git-update.sh',
+
+  # directories
+  datadir => $datadir,
+  testdir => getcwd,
+);
+
+done_testing;
diff --git a/tests/input-types/hg.t b/tests/input-types/hg.t
new file mode 100644
index 00000000..d0bdc8d8
--- /dev/null
+++ b/tests/input-types/hg.t
@@ -0,0 +1,28 @@
+use strict;
+use Cwd;
+use Setup;
+use TestScmInput;
+
+(my $datadir, my $pgsql) = test_init();
+
+require Hydra::Schema;
+require Hydra::Model::DB;
+
+use Test2::V0;
+
+my $db = Hydra::Model::DB->new;
+hydra_setup($db);
+
+# Tests the creation of a Hydra jobset using a hg repo as input.
+testScmInput(
+  type => 'hg',
+  expr => 'hg-input.nix',
+  uri => 'hg-repo',
+  update => 'jobs/hg-update.sh',
+
+  # directories
+  datadir => $datadir,
+  testdir => getcwd,
+);
+
+done_testing;
diff --git a/tests/input-types/svn-checkout.t b/tests/input-types/svn-checkout.t
new file mode 100644
index 00000000..7c8543c3
--- /dev/null
+++ b/tests/input-types/svn-checkout.t
@@ -0,0 +1,28 @@
+use strict;
+use Cwd;
+use Setup;
+use TestScmInput;
+
+(my $datadir, my $pgsql) = test_init();
+
+require Hydra::Schema;
+require Hydra::Model::DB;
+
+use Test2::V0;
+
+my $db = Hydra::Model::DB->new;
+hydra_setup($db);
+
+# Tests the creation of a Hydra jobset using a svn checkout as input.
+testScmInput(
+  type => 'svn-checkout',
+  expr => 'svn-checkout-input.nix',
+  uri => 'svn-checkout-repo',
+  update => 'jobs/svn-checkout-update.sh',
+
+  # directories
+  datadir => $datadir,
+  testdir => getcwd,
+);
+
+done_testing;
diff --git a/tests/input-types/svn.t b/tests/input-types/svn.t
new file mode 100644
index 00000000..091a6c74
--- /dev/null
+++ b/tests/input-types/svn.t
@@ -0,0 +1,28 @@
+use strict;
+use Cwd;
+use Setup;
+use TestScmInput;
+
+(my $datadir, my $pgsql) = test_init();
+
+require Hydra::Schema;
+require Hydra::Model::DB;
+
+use Test2::V0;
+
+my $db = Hydra::Model::DB->new;
+hydra_setup($db);
+
+# Tests the creation of a Hydra jobset using a svn repo as input.
+testScmInput(
+  type => 'svn',
+  expr => 'svn-input.nix',
+  uri => 'svn-repo',
+  update => 'jobs/svn-update.sh',
+
+  # directories
+  datadir => $datadir,
+  testdir => getcwd,
+);
+
+done_testing;
diff --git a/tests/jobs/bzr-checkout-update.sh b/tests/jobs/bzr-checkout-update.sh
index 0aaeca14..7eb56466 100755
--- a/tests/jobs/bzr-checkout-update.sh
+++ b/tests/jobs/bzr-checkout-update.sh
@@ -9,8 +9,14 @@ else
     state=0;
 fi
 
+export BZR_HOME; # Set by the Makefile
 case $state in
     (0) echo "::Create repo. -- continue -- updated::"
+    bzr init bzr-repo
+    bzr whoami "build <build@invalid.org>" -d bzr-repo
+    touch bzr-repo/bzr-file
+    bzr add bzr-repo/bzr-file
+    bzr commit -m "add bzr-file" bzr-repo/bzr-file
     ln -s bzr-repo bzr-checkout-repo
     ;;
     (*) echo "::End. -- stop -- nothing::" ;;
diff --git a/tests/jobs/git-rev-update.sh b/tests/jobs/git-rev-update.sh
index d48268f4..e91af1f9 100755
--- a/tests/jobs/git-rev-update.sh
+++ b/tests/jobs/git-rev-update.sh
@@ -3,6 +3,7 @@ set -e
 
 repo=git-repo
 export HOME=$(pwd)
+export XDG_CONFIG_HOME=$(pwd)/.config
 STATE_FILE=$(pwd)/.git-rev-state
 if test -e $STATE_FILE; then
     state=1
diff --git a/tests/jobs/git-update.sh b/tests/jobs/git-update.sh
index afe59717..7c983ccf 100755
--- a/tests/jobs/git-update.sh
+++ b/tests/jobs/git-update.sh
@@ -4,6 +4,7 @@ set -e
 
 repo=git-repo
 export HOME=$(pwd)
+export XDG_CONFIG_HOME=$(pwd)/.config
 STATE_FILE=$(pwd)/.git-state
 if test -e $STATE_FILE; then
     state=$(cat $STATE_FILE)
diff --git a/tests/jobs/svn-checkout-update.sh b/tests/jobs/svn-checkout-update.sh
index 7aa6c868..01c6c8e9 100755
--- a/tests/jobs/svn-checkout-update.sh
+++ b/tests/jobs/svn-checkout-update.sh
@@ -11,6 +11,11 @@ fi
 
 case $state in
     (0) echo "::Create repo. -- continue -- updated::"
+    svnadmin create svn-repo
+    svn co file://$PWD/$repo svn-checkout
+    touch svn-checkout/svn-file
+    svn add svn-checkout/svn-file
+    svn commit -m "add svn file" svn-checkout/svn-file
     ln -s svn-repo svn-checkout-repo
     ;;
     (*) echo "::End. -- stop -- nothing::" ;;
diff --git a/tests/lib/TestScmInput.pm b/tests/lib/TestScmInput.pm
new file mode 100644
index 00000000..3aa720d0
--- /dev/null
+++ b/tests/lib/TestScmInput.pm
@@ -0,0 +1,74 @@
+package TestScmInput;
+use warnings;
+use strict;
+
+use Exporter;
+use Test2::V0;
+
+use Setup;
+
+our @ISA = qw(Exporter);
+our @EXPORT = qw(testScmInput);
+
+# Generic test for the various SCM types Hydra supports.
+#
+# Takes input in the form of:
+#
+# (
+#   type => "input type",
+#   name => "jobset name", # defaults to the input's type
+#   uri => "uri",
+#   update => "script for updating the input",
+#   datadir => "data dir", # returned from `test_init()` subroutine
+#   testdir => "the hydra tests directory", # usually just `getcwd`
+# )
+#
+# and runs a test that constructs a jobset from the specified input.
+sub testScmInput {
+  # Collect named args, dying if a required arg is missing
+  my %args = @_;
+  my $type = $args{type} // die "required arg 'type' missing";
+  my $expr = $args{expr} // die "required arg 'expr' missing";
+
+  # $name is optional and defaults to $type
+  my $name = $args{name} // $type;
+
+  # Get directories
+  my $testdir = $args{testdir} // die "required arg 'testdir' missing";
+  my $datadir = $args{datadir} // die "required arg 'datadir' missing";
+
+  my $update = $args{update} // die "required arg 'update' missing";
+  $update = "$testdir/$update";
+
+  # Create scratch locations
+  my $scratchdir = "$datadir/scratch";
+  mkdir $scratchdir or die "mkdir($scratchdir): $!\n";
+
+  # $uri and $update are constructed from the directories
+  my $uri = $args{uri} // die "required arg 'uri' missing";
+  $uri = "file://$scratchdir/$uri";
+
+  subtest "With the SCM input named $name" => sub {
+    my $jobset = createJobsetWithOneInput($name, $expr, 'src', $type, $uri);
+
+    my ($mutations, $queueSize) = (0, 0);
+
+    my ($loop, $updated) = updateRepository($name, $update, $scratchdir);
+    while ($loop) {
+      subtest "Mutation number $mutations" => sub {
+        ok(evalSucceeds($jobset), "Evaluating nix-expression.");
+
+        if ($updated) {
+          $queueSize++;
+          is(nrQueuedBuildsForJobset($jobset), $queueSize, "Expect $queueSize jobs in the queue.");
+          ok(evalSucceeds($jobset), "Evaluating nix-expression again.");
+        }
+
+        is(nrQueuedBuildsForJobset($jobset), $queueSize, "Expect deterministic evaluation.");
+
+        $mutations++;
+        ($loop, $updated) = updateRepository($name, $update, $scratchdir);
+      };
+    }
+  };
+}