Fix #2051: Running unit tests from DUB single file packages fails

.github/workflows/main.yml

@@ -63,6 +63,8 @@ jobs:
         # The value doesn't matter as long as it's > 2.087
         FRONTEND: 2.093.0
       run: |
+        dub build --compiler=${{ env.DC }}
+        dub run   --compiler=${{ env.DC }} --single test/issue_2051_running_unittests_from_dub_single_file_packages_fails.d
         ./scripts/ci/travis.sh
 
     - name: '[Windows] Test'
@@ -72,3 +74,4 @@ jobs:
       run: |
         dub build --compiler=${{ env.DC }}
         dub test  --compiler=${{ env.DC }}
+        dub run   --compiler=${{ env.DC }} --single test\issue_2051_running_unittests_from_dub_single_file_packages_fails.d

changelog/fix-2051.dd

@@ -0,0 +1,3 @@
+Fix #2051 "Running unit tests from DUB single file packages fails"
+
+Now dub is capable run test command in single mode like: `dub test --single yoursinglefile.d`

source/dub/dub.d

@@ -663,7 +663,10 @@ class Dub {
 			foreach (file; lbuildsettings.sourceFiles) {
 				if (file.endsWith(".d")) {
 					auto fname = NativePath(file).head.name;
-					if (NativePath(file).relativeTo(m_project.rootPackage.path) == NativePath(mainfil)) {
+					NativePath msf = NativePath(mainfil);
+					if (msf.absolute)
+						msf = msf.relativeTo(m_project.rootPackage.path);
+					if (NativePath(file).relativeTo(m_project.rootPackage.path) == msf) {
 						logWarn("Excluding main source file %s from test.", mainfil);
 						tcinfo.excludedSourceFiles[""] ~= mainfil;
 						continue;

test/.gitignore

@@ -17,3 +17,4 @@ version-spec/**/foo.cmake
 version-spec/**/foo
 
 /test_registry
+/issue_2051_running_unittests_from_dub_single_file_packages_fails

test/issue_2051_running_unittests_from_dub_single_file_packages_fails.d

@@ -0,0 +1,76 @@
+/+ dub.sdl:
+   name "issue_2051_running_unittests_from_dub_single_file_packages_fails"
+ +/
+
+import std.algorithm : any;
+import std.conv : text;
+import std.file : tempDir;
+import std.stdio : File, writeln;
+import std.string : lineSplitter;
+import std.path : buildPath;
+import std.process : environment, executeShell;
+
+auto executeCommand(string command)
+{
+	import std.exception : enforce;
+
+	auto dub = executeShell(command);
+	writeln("--- dub output:");
+	foreach(line; dub.output.lineSplitter)
+		writeln("\t", line);
+	writeln("--- end of dub output");
+
+	enforce(dub.status == 0, "couldn't build the project, see above");
+
+	return dub.output;
+}
+
+/// check dub output to determine rebuild has not been triggered
+auto checkUnittestsResult(string output)
+{
+	if (output.lineSplitter.any!(a=> a == "All unit tests have been run successfully."))
+	{
+		writeln("\nOk. Unittest passed.");
+		return 0;
+	}
+	else
+	{
+		writeln("\nError. Unittests failed.");
+		return 1;
+	}
+}
+
+int main()
+{
+	auto dub = environment.get("DUB");
+	if (!dub.length)
+		dub = buildPath(".", "bin", "dub");
+
+	string filename;
+	// create test_project
+	{
+		filename = tempDir.buildPath("issue_2051.d");
+		auto f = File(filename, "w");
+		f.write(
+`#!/usr/bin/env dub
+/+ dub.sdl:
+	name "issue2051"
++/
+
+version(unittest) {}
+else void main()
+{
+}
+
+unittest
+{
+	auto input = [1721];
+	assert(input[0] == 1721);
+}
+`		);
+	}
+
+	return text(dub, " test --single ", filename)
+		.executeCommand
+		.checkUnittestsResult;
+}