1 files changed, 131 insertions, 0 deletions
diff --git a/cli/lsp/refactor.rs b/cli/lsp/refactor.rs
new file mode 100644
index 000000000..17ab4d5de
--- /dev/null
+++ b/cli/lsp/refactor.rs
@@ -0,0 +1,131 @@
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+
+// The logic of this module is heavily influenced by
+// https://github.com/microsoft/vscode/blob/main/extensions/typescript-language-features/src/languageFeatures/refactor.ts
+
+use deno_core::serde::Deserialize;
+use deno_core::serde::Serialize;
+use deno_core::ModuleSpecifier;
+use lspower::lsp;
+
+pub struct RefactorCodeActionKind {
+  pub kind: lsp::CodeActionKind,
+  matches_callback: Box<dyn Fn(&str) -> bool + Send + Sync>,
+}
+
+impl RefactorCodeActionKind {
+  pub fn matches(&self, tag: &str) -> bool {
+    (self.matches_callback)(tag)
+  }
+}
+
+lazy_static::lazy_static! {
+  pub static ref EXTRACT_FUNCTION: RefactorCodeActionKind = RefactorCodeActionKind {
+    kind : [lsp::CodeActionKind::REFACTOR_EXTRACT.as_str(), "function"].join(".").into(),
+    matches_callback: Box::new(|tag: &str| tag.starts_with("function_")),
+  };
+
+  pub static ref EXTRACT_CONSTANT: RefactorCodeActionKind = RefactorCodeActionKind {
+    kind : [lsp::CodeActionKind::REFACTOR_EXTRACT.as_str(), "constant"].join(".").into(),
+    matches_callback: Box::new(|tag: &str| tag.starts_with("constant_")),
+  };
+
+  pub static ref EXTRACT_TYPE: RefactorCodeActionKind = RefactorCodeActionKind {
+    kind : [lsp::CodeActionKind::REFACTOR_EXTRACT.as_str(), "type"].join(".").into(),
+    matches_callback: Box::new(|tag: &str| tag.starts_with("Extract to type alias")),
+  };
+
+  pub static ref EXTRACT_INTERFACE: RefactorCodeActionKind = RefactorCodeActionKind {
+    kind : [lsp::CodeActionKind::REFACTOR_EXTRACT.as_str(), "interface"].join(".").into(),
+    matches_callback: Box::new(|tag: &str| tag.starts_with("Extract to interface")),
+  };
+
+  pub static ref MOVE_NEWFILE: RefactorCodeActionKind = RefactorCodeActionKind {
+    kind : [lsp::CodeActionKind::REFACTOR.as_str(), "move", "newFile"].join(".").into(),
+    matches_callback: Box::new(|tag: &str| tag.starts_with("Move to a new file")),
+  };
+
+  pub static ref REWRITE_IMPORT: RefactorCodeActionKind = RefactorCodeActionKind {
+    kind : [lsp::CodeActionKind::REFACTOR_REWRITE.as_str(), "import"].join(".").into(),
+    matches_callback: Box::new(|tag: &str| tag.starts_with("Convert namespace import") || tag.starts_with("Convert named imports")),
+  };
+
+  pub static ref REWRITE_EXPORT: RefactorCodeActionKind = RefactorCodeActionKind {
+    kind : [lsp::CodeActionKind::REFACTOR_REWRITE.as_str(), "export"].join(".").into(),
+    matches_callback: Box::new(|tag: &str| tag.starts_with("Convert default export") || tag.starts_with("Convert named export")),
+  };
+
+  pub static ref REWRITE_ARROW_BRACES: RefactorCodeActionKind = RefactorCodeActionKind {
+    kind : [lsp::CodeActionKind::REFACTOR_REWRITE.as_str(), "arrow", "braces"].join(".").into(),
+    matches_callback: Box::new(|tag: &str| tag.starts_with("Add or remove braces in an arrow function")),
+  };
+
+  pub static ref REWRITE_PARAMETERS_TO_DESTRUCTURED: RefactorCodeActionKind = RefactorCodeActionKind {
+    kind : [lsp::CodeActionKind::REFACTOR_REWRITE.as_str(), "parameters", "toDestructured"].join(".").into(),
+    matches_callback: Box::new(|tag: &str| tag.starts_with("Convert parameters to destructured object")),
+  };
+
+  pub static ref REWRITE_PROPERTY_GENERATEACCESSORS: RefactorCodeActionKind = RefactorCodeActionKind {
+    kind : [lsp::CodeActionKind::REFACTOR_REWRITE.as_str(), "property", "generateAccessors"].join(".").into(),
+    matches_callback: Box::new(|tag: &str| tag.starts_with("Generate 'get' and 'set' accessors")),
+  };
+
+  pub static ref ALL_KNOWN_REFACTOR_ACTION_KINDS: Vec<&'static RefactorCodeActionKind> = vec![
+    &EXTRACT_FUNCTION,
+    &EXTRACT_CONSTANT,
+    &EXTRACT_TYPE,
+    &EXTRACT_INTERFACE,
+    &MOVE_NEWFILE,
+    &REWRITE_IMPORT,
+    &REWRITE_EXPORT,
+    &REWRITE_ARROW_BRACES,
+    &REWRITE_PARAMETERS_TO_DESTRUCTURED,
+    &REWRITE_PROPERTY_GENERATEACCESSORS
+  ];
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct RefactorCodeActionData {
+  pub specifier: ModuleSpecifier,
+  pub range: lsp::Range,
+  pub refactor_name: String,
+  pub action_name: String,
+}
+
+pub fn prune_invalid_actions(
+  actions: &[lsp::CodeAction],
+  number_of_invalid: usize,
+) -> Vec<lsp::CodeAction> {
+  let mut available_actions = Vec::<lsp::CodeAction>::new();
+  let mut invalid_common_actions = Vec::<lsp::CodeAction>::new();
+  let mut invalid_uncommon_actions = Vec::<lsp::CodeAction>::new();
+  for action in actions {
+    if action.disabled.is_none() {
+      available_actions.push(action.clone());
+      continue;
+    }
+
+    // These are the common refactors that we should always show if applicable.
+    let action_kind =
+      action.kind.as_ref().map(|a| a.as_str()).unwrap_or_default();
+    if action_kind.starts_with(EXTRACT_CONSTANT.kind.as_str())
+      || action_kind.starts_with(EXTRACT_FUNCTION.kind.as_str())
+    {
+      invalid_common_actions.push(action.clone());
+      continue;
+    }
+
+    // These are the remaining refactors that we can show if we haven't reached the max limit with just common refactors.
+    invalid_uncommon_actions.push(action.clone());
+  }
+
+  let mut prioritized_actions = Vec::<lsp::CodeAction>::new();
+  prioritized_actions.extend(invalid_common_actions);
+  prioritized_actions.extend(invalid_uncommon_actions);
+  let top_n_invalid = prioritized_actions
+    [0..std::cmp::min(number_of_invalid, prioritized_actions.len())]
+    .to_vec();
+  available_actions.extend(top_n_invalid);
+  available_actions
+}