feat: client effective runtimes list (#490)

* feat: repositories accessor

* feat: repository and templates client api

- Templates management api
- Repositories management api expansion

* fix: nil pointer reference on generate

* src: test temp directory name consistency and comment improvements

* feat: runtimes accessor

client.go

@@ -686,6 +686,30 @@ func (c *Client) Emit(ctx context.Context, endpoint string) error {
 	return c.emitter.Emit(ctx, endpoint)
 }
 
+// Runtimes available in totality.
+// Not all repository/template combinations necessarily exist,
+// and further validation is performed when a template+runtime is chosen.
+// from a given repository.  This is the global list of all available.
+// Returned list is unique and sorted.
+func (c *Client) Runtimes() ([]string, error) {
+	runtimes := newSortedSet()
+
+	// Gather all runtimes from all repositories
+	// into a uniqueness map
+	repositories, err := c.Repositories.All()
+	if err != nil {
+		return []string{}, err
+	}
+	for _, repo := range repositories {
+		for _, runtime := range repo.Runtimes {
+			runtimes.Add(runtime)
+		}
+	}
+
+	// Return a unique, sorted list of runtimes
+	return runtimes.Items(), nil
+}
+
 // sorted set of strings.
 //
 // write-optimized and suitable only for fairly small values of N.

client_test.go

@@ -831,6 +831,50 @@ func TestWithConfiguredBuildpacks(t *testing.T) {
 	}
 }
 
+// TestRuntimes ensures that the total set of runtimes are returned.
+func TestRuntimes(t *testing.T) {
+	// TODO: test when a specific repo override is indicated
+	// (remote repo which takes precidence over embedded and extended)
+
+	client := fn.New(fn.WithRepositories("testdata/repositories"))
+
+	runtimes, err := client.Runtimes()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Runtimes from `./templates` + `./testdata/repositories`
+	// Should be unique and sorted.
+	//
+	// Note that hard-coding the runtimes list here does add future maintenance
+	// (test will fail requiring updates when either the builtin set of or test
+	//  set change), but the simplicity and straightforwardness of this
+	// requirement seems to outweigh the complexity of calculating the list for
+	// testing, which effectively just recreates the logic within the client.
+	// Additionally, this list has the benefit of creating a more understandable
+	// test (a primary goal of course being human communication of libray intent).
+	// If this is an incorrect assumption, we would need to calculate this
+	// slice from the contents of ./templates & ./testdata/repositories, taking
+	// into acount future repository manifests.
+	expected := []string{
+		"customRuntime",
+		"go",
+		"node",
+		"python",
+		"quarkus",
+		"rust",
+		"springboot",
+		"test",
+		"typescript",
+	}
+
+	if !reflect.DeepEqual(runtimes, expected) {
+		t.Logf("expected: %v", expected)
+		t.Logf("received: %v", runtimes)
+		t.Fatal("Runtimes not as expected.")
+	}
+}
+
 // Helpers ----
 
 // USING:  Make specified dir.  Return deferrable cleanup fn.

repositories.go

@@ -98,10 +98,10 @@ func (r *Repositories) Add(name, uri string) (err error) {
 }
 
 // Rename a repository
-func (r *Repositories) Rename(old string, new string) error {
+func (r *Repositories) Rename(from, to string) error {
-	oldPath := filepath.Join(r.Path, old)
+	a := filepath.Join(r.Path, from)
-	newPath := filepath.Join(r.Path, new)
+	b := filepath.Join(r.Path, to)
-	return os.Rename(oldPath, newPath)
+	return os.Rename(a, b)
 }
 
 // Remove a repository of the given name from the repositories.

repositories_test.go

@@ -48,7 +48,7 @@ func TestRepositoriesGet(t *testing.T) {
 
 	// valid should have expected name
 	if repo.Name != "customProvider" {
-		t.Fatalf("expected 'customProvider' as repository name, got: %v", repo.Name)
+		t.Fatalf("Expected 'customProvider', got: %v", repo.Name)
 	}
 }