Add Go module collection support

.dagger/modules/e2e/main.dang

@@ -19,10 +19,8 @@ type E2e {
       .length > 0
   }
 
-  let containsModulePath(mods: [{{path: String!}}!]!, want: String!): Boolean! {
-    mods
-      .filter { mod => mod.path == want }
-      .length > 0
+  let containsModulePath(paths: [String!]!, want: String!): Boolean! {
+    containsPath(paths, want)
   }
 
   """
@@ -79,7 +77,8 @@ type E2e {
       "module lookup unexpectedly snapped with findUp false: " + direct.path,
     )
 
-    let allModulePaths = go(version: "1.25").modules(ws).{path}
+    let allModules = go(version: "1.25").modules(ws)
+    let allModulePaths = allModules.keys
     assert(
       containsModulePath(allModulePaths, "fixtures/go-module-cross-include-a"),
       "unfiltered modules did not include expected fixture module",
@@ -92,10 +91,14 @@ type E2e {
       containsModulePath(allModulePaths, "testdata/go-module-excluded"),
       "unfiltered modules did not include skipped fixture module by default",
     )
+    assert(
+      allModules.get(key: "testdata/go-module-with-testdata").path == "testdata/go-module-with-testdata",
+      "module collection get did not return the requested module",
+    )
 
     let includedModulePaths = go(version: "1.25")
       .modules(ws, include: ["fixtures/go-module-cross-include-a"])
-      .{path}
+      .keys
     assert(
       containsModulePath(includedModulePaths, "fixtures/go-module-cross-include-a"),
       "modules include filter did not include matching module root",
@@ -107,7 +110,7 @@ type E2e {
 
     let excludedModulePaths = go(version: "1.25")
       .modules(ws, exclude: ["fixtures/go-module-cross-include-a"])
-      .{path}
+      .keys
     assert(
       containsModulePath(excludedModulePaths, "fixtures/go-module-cross-include-a") == false,
       "modules exclude filter included excluded module root",
@@ -119,7 +122,7 @@ type E2e {
         include: ["fixtures/go-module-cross-include-*"],
         exclude: ["fixtures/go-module-cross-include-b"],
       )
-      .{path}
+      .keys
     assert(
       containsModulePath(combinedModulePaths, "fixtures/go-module-cross-include-a"),
       "modules combined filters did not include matching module root",
@@ -131,7 +134,7 @@ type E2e {
 
     let contentMatchedModulePaths = go(version: "1.25")
       .modules(ws, include: ["**/module-a-only.data"])
-      .{path}
+      .keys
     assert(
       containsModulePath(contentMatchedModulePaths, "fixtures/go-module-cross-include-a"),
       "modules include filter did not match module directory contents",
@@ -143,7 +146,7 @@ type E2e {
 
     let lintSkippedModulePaths = go(version: "1.25")
       .modules(ws, includeSkipLint: false)
-      .{path}
+      .keys
     assert(
       containsModulePath(lintSkippedModulePaths, "testdata/go-module-excluded") == false,
       "modules includeSkipLint false included lint-skipped module",
@@ -163,7 +166,7 @@ type E2e {
 
     let testSkippedModulePaths = go(version: "1.25")
       .modules(ws, includeSkipTest: false)
-      .{path}
+      .keys
     assert(
       containsModulePath(testSkippedModulePaths, "testdata/go-module-excluded") == false,
       "modules includeSkipTest false included test-skipped module",
@@ -183,7 +186,7 @@ type E2e {
 
     let generateSkippedModulePaths = go(version: "1.25")
       .modules(ws, includeSkipGenerate: false)
-      .{path}
+      .keys
     assert(
       containsModulePath(generateSkippedModulePaths, "testdata/go-module-excluded") == false,
       "modules includeSkipGenerate false included generate-skipped module",

go.dang

@@ -33,7 +33,7 @@ type Go {
   pub skipGenerateFilename: String! = ".dagger-skip-go-generate"
 
   """
-  Return every Go module discovered from workspace go.mod files.
+  Return Go modules discovered from workspace go.mod files.
   Optional include/exclude patterns filter discovered module root directories.
   """
   pub modules(
@@ -43,7 +43,7 @@ type Go {
     includeSkipLint: Boolean! = true,
     includeSkipTest: Boolean! = true,
     includeSkipGenerate: Boolean! = true,
-  ): [GoModule!]! {
+  ): GoModules! {
     let lintSkipMarkers = ws
       .directory("/", include: ["**/" + skipLintFilename])
       .glob("**/" + skipLintFilename)
@@ -54,7 +54,7 @@ type Go {
       .directory("/", include: ["**/" + skipGenerateFilename])
       .glob("**/" + skipGenerateFilename)
 
-    ws
+    let paths = ws
       .directory("/", include: ["**/go.mod"])
       .glob("**/go.mod")
       .map { modPath =>
@@ -81,6 +81,19 @@ type Go {
         (includeSkipTest or mod.skipTest(ws) == false) and
         (includeSkipGenerate or mod.skipGenerate(ws) == false)
       }
+      .map { mod => mod.path }
+
+    GoModules(
+      paths: paths,
+      version: version,
+      includeExtraFiles: includeExtraFiles,
+      skipLintFilename: skipLintFilename,
+      skipTestFilename: skipTestFilename,
+      skipGenerateFilename: skipGenerateFilename,
+      lintSkipMarkers: lintSkipMarkers,
+      testSkipMarkers: testSkipMarkers,
+      generateSkipMarkers: generateSkipMarkers,
+    )
   }
 
   let modulePathIncluded(
@@ -148,7 +161,9 @@ type Go {
   Modules with the lint skip marker are skipped.
   """
   pub lintAll(ws: Workspace!): Void @check {
-    let layers = modules(ws).reduce(directory) { layers, mod =>
+    let mods = modules(ws)
+    let layers = mods.paths.reduce(directory) { layers, path =>
+      let mod = mods.module(path)
       layers.withDirectory(
         mod.path,
         directory.withFile("go.mod", mod.lintExec(ws).file("go.mod")),
@@ -167,7 +182,10 @@ type Go {
   Modules with the test skip marker are skipped.
   """
   pub testAll(ws: Workspace!): Void @check {
-    let mods = modules(ws).filter { mod => mod.skipTest(ws) == false }
+    let collection = modules(ws)
+    let mods = collection.paths.map { path => collection.module(path) }.filter { mod =>
+      mod.skipTest(ws) == false
+    }
     let layers = mods.reduce(directory) { layers, mod =>
       layers.withDirectory(
         mod.path,
@@ -188,7 +206,8 @@ type Go {
   are skipped.
   """
   pub generateAll(ws: Workspace!): Changeset! @generate {
-    let mods = modules(ws).filter { mod =>
+    let collection = modules(ws)
+    let mods = collection.paths.map { path => collection.module(path) }.filter { mod =>
       mod.skipGenerate(ws) == false and mod.hasGenerateDirectives(ws)
     }
 
@@ -208,6 +227,42 @@ type Go {
 
 }
 
+"""
+Go modules discovered in a workspace.
+"""
+type GoModules {
+  """
+  Workspace-relative module root paths in discovery order.
+  """
+  pub paths: [String!]! @keys
+
+  let version: String!
+  let includeExtraFiles: [String!]!
+  let skipLintFilename: String!
+  let skipTestFilename: String!
+  let skipGenerateFilename: String!
+  let lintSkipMarkers: [String!]!
+  let testSkipMarkers: [String!]!
+  let generateSkipMarkers: [String!]!
+
+  """
+  Return the discovered Go module with the given workspace-relative root path.
+  """
+  pub module(path: String!): GoModule! @get {
+    GoModule(
+      path: path,
+      version: version,
+      includeExtraFiles: includeExtraFiles,
+      skipLintFilename: skipLintFilename,
+      skipTestFilename: skipTestFilename,
+      skipGenerateFilename: skipGenerateFilename,
+      lintSkipMarkers: lintSkipMarkers,
+      testSkipMarkers: testSkipMarkers,
+      generateSkipMarkers: generateSkipMarkers,
+    )
+  }
+}
+
 """
 A Go module rooted at a workspace-relative path.
 """