feat: Add "deno doc" subcommand (#4500)

1 files changed, 70 insertions, 0 deletions

diff --git a/cli/doc/function.rs b/cli/doc/function.rs
new file mode 100644
index 000000000..ec7f9bf38
--- /dev/null
+++ b/cli/doc/function.rs
@@ -0,0 +1,70 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+use serde::Serialize;
+use swc_ecma_ast;
+
+use super::parser::DocParser;
+use super::ts_type::ts_type_ann_to_def;
+use super::ts_type::TsTypeDef;
+use super::ParamDef;
+
+#[derive(Debug, Serialize, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct FunctionDef {
+  pub params: Vec<ParamDef>,
+  pub return_type: Option<TsTypeDef>,
+  pub is_async: bool,
+  pub is_generator: bool,
+  // TODO: type_params, decorators
+}
+
+pub fn function_to_function_def(
+  doc_parser: &DocParser,
+  function: &swc_ecma_ast::Function,
+) -> FunctionDef {
+  let mut params = vec![];
+
+  for param in &function.params {
+    use swc_ecma_ast::Pat;
+
+    let param_def = match param {
+      Pat::Ident(ident) => {
+        let ts_type = ident
+          .type_ann
+          .as_ref()
+          .map(|rt| ts_type_ann_to_def(&doc_parser.source_map, rt));
+
+        ParamDef {
+          name: ident.sym.to_string(),
+          ts_type,
+        }
+      }
+      _ => ParamDef {
+        name: "<TODO>".to_string(),
+        ts_type: None,
+      },
+    };
+
+    params.push(param_def);
+  }
+
+  let maybe_return_type = function
+    .return_type
+    .as_ref()
+    .map(|rt| ts_type_ann_to_def(&doc_parser.source_map, rt));
+
+  FunctionDef {
+    params,
+    return_type: maybe_return_type,
+    is_async: function.is_async,
+    is_generator: function.is_generator,
+  }
+}
+
+pub fn get_doc_for_fn_decl(
+  doc_parser: &DocParser,
+  fn_decl: &swc_ecma_ast::FnDecl,
+) -> (String, FunctionDef) {
+  let name = fn_decl.ident.sym.to_string();
+  let fn_def = function_to_function_def(doc_parser, &fn_decl.function);
+  (name, fn_def)
+}