fix(golang-rewrite): allow missing post-plugin-update callback during…

… plugin update (#1849)

docs/guide/upgrading-from-v0-15-to-v0-16.md

@@ -8,11 +8,6 @@ rather than a set of scripts.
 
 ## Breaking Changes
 
-### `download` is now a required callback for plugins
-
-Previously `download` was optional, now it is required. If a plugin lacks this
-callback any installs of any version of that plugin will fail.
-
 ### Hyphenated commands have been removed
 
 asdf version 0.15.0 and earlier supported by hyphenated and non-hyphenated

docs/plugins/create.md

@@ -34,7 +34,7 @@ The full list of scripts callable from asdf.
 | Script                                                                                                | Description                                                      |
 | :---------------------------------------------------------------------------------------------------- |:-----------------------------------------------------------------|
 | [bin/list-all](#bin-list-all) <Badge type="tip" text="required" vertical="middle" />                  | List all installable versions                                    |
-| [bin/download](#bin-download) <Badge type="tip" text="required" vertical="middle" />                  | Download source code or binary for the specified version         |
+| [bin/download](#bin-download) <Badge type="warning" text="recommended" vertical="middle" />           | Download source code or binary for the specified version         |
 | [bin/install](#bin-install) <Badge type="tip" text="required" vertical="middle" />                    | Installs the specified version                                   |
 | [bin/latest-stable](#bin-latest-stable) <Badge type="warning" text="recommended" vertical="middle" /> | List the latest stable version of the specified tool             |
 | [bin/help.overview](#bin-help.overview)                                                               | Output a general description about the plugin & tool             |

internal/plugins/plugins.go

@@ -261,11 +261,14 @@ func (p Plugin) Update(conf config.Config, ref string, out, errout io.Writer) (s
 	}
 
 	err = p.RunCallback("post-plugin-update", []string{}, env, out, errout)
+	if _, ok := err.(NoCallbackError); err != nil && !ok {
+		return newRef, err
+	}
 
 	hook.Run(conf, "post_asdf_plugin_update", []string{p.Name})
 	hook.Run(conf, fmt.Sprintf("post_asdf_plugin_update_%s", p.Name), []string{})
 
-	return newRef, err
+	return newRef, nil
 }
 
 // List takes config and flags for what to return and builds a list of plugins

internal/plugins/plugins_test.go

@@ -231,9 +231,13 @@ func TestUpdate(t *testing.T) {
 
 	repoPath, err := repotest.GeneratePlugin("dummy_plugin", testDataDir, testPluginName)
 	assert.Nil(t, err)
+	assert.Nil(t, Add(conf, testPluginName, repoPath, ""))
 
-	err = Add(conf, testPluginName, repoPath, "")
+	noPostUpdateCallbackPlugin := "no-post-update"
+	repoPath, err = repotest.GeneratePlugin("dummy_plugin", testDataDir, noPostUpdateCallbackPlugin)
 	assert.Nil(t, err)
+	assert.Nil(t, os.Remove(filepath.Join(repoPath, "bin", "post-plugin-update")))
+	assert.Nil(t, Add(conf, noPostUpdateCallbackPlugin, repoPath, ""))
 
 	badPluginName := "badplugin"
 	badRepo := data.PluginDirectory(testDataDir, badPluginName)
@@ -272,6 +276,14 @@ func TestUpdate(t *testing.T) {
 			wantSomeRef: true,
 			wantErrMsg:  "",
 		},
+		{
+			desc:        "updates plugin when plugin when post-plugin-update callback does not exist",
+			givenConf:   conf,
+			givenName:   noPostUpdateCallbackPlugin,
+			givenRef:    "",
+			wantSomeRef: true,
+			wantErrMsg:  "",
+		},
 	}
 
 	for _, tt := range tests {