Discover Go tests by static regex instead of go test -list

GoDirectory.tests used to spin up a Go container and parse 'go test -list' stdout to enumerate test names. Replace that with a single Workspace.directory(...).search(pattern: "^func Test\\w+\\(") over the directory's *_test.go files and parse names from the matched lines in Dang. This is much faster (no compile, no container exec) and matches the same set go test -list does for top-level test functions. Test methods on testify-style suites are intentionally not listed: they cannot be selected with go test -run independently of their parent function. Add moduleIntrospectionCheck assertions covering the new GoTestDirs and GoTests collection surface end-to-end: keys/get round-trip on both levels, multi-test discovery from a single *_test.go file (cross- include-b has two top-level tests), and that a skip-configured directory produces an empty tests collection. Signed-off-by: Solomon Hykes <solomon@dagger.io>
dagger · dagger-codex · Jun 1, 2026 · Jun 10, 2026 · Jun 11, 2026 · Jun 12, 2026
commit 6ea03faa593c2fb80c9333d4934547831e70ef79
diff --git a/.dagger/modules/e2e/main.dang b/.dagger/modules/e2e/main.dang
@@ -433,6 +433,56 @@ type E2e {
       ),
       "go:generate scoped include did not include generator support files",
     )
+
+    # Test directory collection surface and static test discovery.
+    # cross-include-b has two top-level Test functions in a single file —
+    # exercises ripgrep-based listing and multi-match handling.
+    let crossB = tool.module(ws, "fixtures/go-module-cross-include-b")
+    let crossBTestDirs = crossB.testDirs(ws)
+    assert(
+      containsPath(crossBTestDirs.keys, "fixtures/go-module-cross-include-b"),
+      "testDirs collection did not include expected test directory",
+    )
+    assert(
+      crossBTestDirs
+        .get(key: "fixtures/go-module-cross-include-b")
+        .path == "fixtures/go-module-cross-include-b",
+      "testDirs collection get did not return the requested directory",
+    )
+
+    let crossBTests = crossBTestDirs
+      .get(key: "fixtures/go-module-cross-include-b")
+      .tests()
+    assert(
+      crossBTests.keys.length == 2,
+      "tests collection did not discover expected number of tests",
+    )
+    assert(
+      containsPath(crossBTests.keys, "TestSiblingModuleDirectiveIncludeIsNotMounted"),
+      "tests collection did not include expected test name",
+    )
+    assert(
+      containsPath(crossBTests.keys, "TestSiblingModuleTestdataIsNotMounted"),
+      "tests collection did not include second test from same file",
+    )
+    assert(
+      crossBTests
+        .get(key: "TestSiblingModuleDirectiveIncludeIsNotMounted")
+        .name == "TestSiblingModuleDirectiveIncludeIsNotMounted",
+      "tests collection get did not return the requested test",
+    )
+
+    # Skip-configured directory should report no tests at all.
+    let skippedTests = tool
+      .module(ws, "testdata/go-module-excluded")
+      .testDirs(ws)
+      .get(key: "testdata/go-module-excluded")
+      .tests()
+    assert(
+      skippedTests.keys.length == 0,
+      "tests collection on a skipped directory was not empty",
+    )
+
     null
   }
 

diff --git a/go.dang b/go.dang
@@ -865,15 +865,26 @@ type GoDirectory {
   """
   The tests in this directory, as a collection keyed by test name.
   Skipped directories produce an empty collection.
+
+  Test names are discovered by statically matching top-level test function
+  declarations in *_test.go files, without compiling or running go test.
   """
   pub tests(): GoTests! {
     let names = if (skipTest) {
       []
     } else {
-      testContainer()
-        .withExec(["sh", "-c", "go test -list '.*' . | grep '^Test' || true"])
-        .stdout
-        .split("\n")
+      let glob = if (path == ".") {
+        "*_test.go"
+      } else {
+        path.trimSuffix("/") + "/*_test.go"
+      }
+      ws
+        .directory("/", include: [glob])
+        .search(pattern: "^func Test\\w+\\(")
+        .{matchedLines}
+        .map { result =>
+          result.matchedLines.trimSpace.trimPrefix("func ").split("(")[0] ?? ""
+        }
         .filter { name => name != "" }
     }
     GoTests(names: names, dir: self)