feat(lsp): provide completions from import map if available (#13624)

Closes #13619 

7 files changed, 351 insertions, 7 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 695e9ba7c..49d478a00 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1935,9 +1935,9 @@ checksum = "cb56e1aa765b4b4f3aadfab769793b7087bb03a4ea4920644a6d238e2df5b9ed"
 
 [[package]]
 name = "import_map"
-version = "0.6.0"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f64f821df8ee00a0fba2dde6296af519eff7d823542b057c1b8c40ca1d58f4c"
+checksum = "09ae88504e9128c4c181a0a4726d868d52aa76de270c7fb00c3c40a8f4fbace4"
 dependencies = [
  "indexmap",
  "log",
diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index 2001a1d44..1943a635f 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -68,7 +68,7 @@ encoding_rs = "=0.8.29"
 env_logger = "=0.8.4"
 fancy-regex = "=0.7.1"
 http = "=0.2.4"
-import_map = "=0.6.0"
+import_map = "=0.8.0"
 jsonc-parser = { version = "=0.19.0", features = ["serde"] }
 libc = "=0.2.106"
 log = { version = "=0.4.14", features = ["serde"] }
diff --git a/cli/lsp/completions.rs b/cli/lsp/completions.rs
index c3026697a..5a09ada61 100644
--- a/cli/lsp/completions.rs
+++ b/cli/lsp/completions.rs
@@ -21,7 +21,14 @@ use deno_core::serde::Deserialize;
 use deno_core::serde::Serialize;
 use deno_core::url::Position;
 use deno_core::ModuleSpecifier;
+use import_map::ImportMap;
 use lspower::lsp;
+use once_cell::sync::Lazy;
+use regex::Regex;
+use std::sync::Arc;
+
+static FILE_PROTO_RE: Lazy<Regex> =
+  Lazy::new(|| Regex::new(r#"^file:/{2}(?:/[A-Za-z]:)?"#).unwrap());
 
 const CURRENT_PATH: &str = ".";
 const PARENT_PATH: &str = "..";
@@ -126,12 +133,22 @@ pub(crate) async fn get_import_completions(
   client: Client,
   module_registries: &ModuleRegistry,
   documents: &Documents,
+  maybe_import_map: Option<Arc<ImportMap>>,
 ) -> Option<lsp::CompletionResponse> {
   let document = documents.get(specifier)?;
   let (text, _, range) = document.get_maybe_dependency(position)?;
   let range = to_narrow_lsp_range(&document.text_info(), &range);
-  // completions for local relative modules
-  if text.starts_with("./") || text.starts_with("../") {
+  if let Some(completion_list) = get_import_map_completions(
+    specifier,
+    &text,
+    &range,
+    maybe_import_map.clone(),
+    documents,
+  ) {
+    // completions for import map specifiers
+    Some(lsp::CompletionResponse::List(completion_list))
+  } else if text.starts_with("./") || text.starts_with("../") {
+    // completions for local relative modules
     Some(lsp::CompletionResponse::List(lsp::CompletionList {
       is_incomplete: false,
       items: get_local_completions(specifier, &text, &range)?,
@@ -155,6 +172,8 @@ pub(crate) async fn get_import_completions(
     });
     Some(lsp::CompletionResponse::List(list))
   } else {
+    // the import specifier is empty, so provide all possible specifiers we are
+    // aware of
     let mut items: Vec<lsp::CompletionItem> = LOCAL_PATHS
       .iter()
       .map(|s| lsp::CompletionItem {
@@ -167,6 +186,9 @@ pub(crate) async fn get_import_completions(
       })
       .collect();
     let mut is_incomplete = false;
+    if let Some(import_map) = maybe_import_map {
+      items.extend(get_base_import_map_completions(import_map.as_ref()));
+    }
     if let Some(origin_items) =
       module_registries.get_origin_completions(&text, &range)
     {
@@ -177,10 +199,133 @@ pub(crate) async fn get_import_completions(
       is_incomplete,
       items,
     }))
-    // TODO(@kitsonk) add bare specifiers from import map
   }
 }
 
+/// When the specifier is an empty string, return all the keys from the import
+/// map as completion items.
+fn get_base_import_map_completions(
+  import_map: &ImportMap,
+) -> Vec<lsp::CompletionItem> {
+  import_map
+    .imports_keys()
+    .iter()
+    .map(|key| {
+      // for some strange reason, keys that start with `/` get stored in the
+      // import map as `file:///`, and so when we pull the keys out, we need to
+      // change the behavior
+      let mut label = if key.starts_with("file://") {
+        FILE_PROTO_RE.replace(key, "").to_string()
+      } else {
+        key.to_string()
+      };
+      let kind = if key.ends_with('/') {
+        label.pop();
+        Some(lsp::CompletionItemKind::FOLDER)
+      } else {
+        Some(lsp::CompletionItemKind::FILE)
+      };
+      lsp::CompletionItem {
+        label: label.clone(),
+        kind,
+        detail: Some("(import map)".to_string()),
+        sort_text: Some(label.clone()),
+        insert_text: Some(label),
+        ..Default::default()
+      }
+    })
+    .collect()
+}
+
+/// Given an existing specifier, return any completions that could apply derived
+/// from the import map. There are two main type of import map keys, those that
+/// a literal, which don't end in `/`, which expects a one for one replacement
+/// of specifier to specifier, and then those that end in `/` which indicates
+/// that the path post the `/` should be appended to resolved specifier. This
+/// handles both cases, pulling any completions from the workspace completions.
+fn get_import_map_completions(
+  specifier: &ModuleSpecifier,
+  text: &str,
+  range: &lsp::Range,
+  maybe_import_map: Option<Arc<ImportMap>>,
+  documents: &Documents,
+) -> Option<lsp::CompletionList> {
+  if !text.is_empty() {
+    if let Some(import_map) = maybe_import_map {
+      let mut items = Vec::new();
+      for key in import_map.imports_keys() {
+        // for some reason, the import_map stores keys that begin with `/` as
+        // `file:///` in its index, so we have to reverse that here
+        let key = if key.starts_with("file://") {
+          FILE_PROTO_RE.replace(key, "").to_string()
+        } else {
+          key.to_string()
+        };
+        if text.starts_with(&key) && key.ends_with('/') {
+          if let Ok(resolved) = import_map.resolve(&key, specifier) {
+            let resolved = resolved.to_string();
+            let workspace_items: Vec<lsp::CompletionItem> = documents
+              .documents(false, true)
+              .into_iter()
+              .filter_map(|d| {
+                let specifier_str = d.specifier().to_string();
+                let new_text = specifier_str.replace(&resolved, &key);
+                if specifier_str.starts_with(&resolved) {
+                  let label = specifier_str.replace(&resolved, "");
+                  let text_edit =
+                    Some(lsp::CompletionTextEdit::Edit(lsp::TextEdit {
+                      range: *range,
+                      new_text: new_text.clone(),
+                    }));
+                  Some(lsp::CompletionItem {
+                    label,
+                    kind: Some(lsp::CompletionItemKind::MODULE),
+                    detail: Some("(import map)".to_string()),
+                    sort_text: Some("1".to_string()),
+                    filter_text: Some(new_text),
+                    text_edit,
+                    ..Default::default()
+                  })
+                } else {
+                  None
+                }
+              })
+              .collect();
+            items.extend(workspace_items);
+          }
+        } else if key.starts_with(text) && text != key {
+          let mut label = key.to_string();
+          let kind = if key.ends_with('/') {
+            label.pop();
+            Some(lsp::CompletionItemKind::FOLDER)
+          } else {
+            Some(lsp::CompletionItemKind::MODULE)
+          };
+          let text_edit = Some(lsp::CompletionTextEdit::Edit(lsp::TextEdit {
+            range: *range,
+            new_text: label.clone(),
+          }));
+          items.push(lsp::CompletionItem {
+            label: label.clone(),
+            kind,
+            detail: Some("(import map)".to_string()),
+            sort_text: Some("1".to_string()),
+            text_edit,
+            ..Default::default()
+          });
+        }
+        if !items.is_empty() {
+          return Some(lsp::CompletionList {
+            items,
+            is_incomplete: false,
+          });
+        }
+      }
+    }
+  }
+  None
+}
+
 /// Return local completions that are relative to the base specifier.
 fn get_local_completions(
   base: &ModuleSpecifier,
diff --git a/cli/lsp/language_server.rs b/cli/lsp/language_server.rs
index bf7be3ea7..e561e5d4e 100644
--- a/cli/lsp/language_server.rs
+++ b/cli/lsp/language_server.rs
@@ -1649,6 +1649,7 @@ impl Inner {
       self.client.clone(),
       &self.module_registries,
       &self.documents,
+      self.maybe_import_map.clone(),
     )
     .await
     {
diff --git a/cli/proc_state.rs b/cli/proc_state.rs
index 320e20ac4..5b347d169 100644
--- a/cli/proc_state.rs
+++ b/cli/proc_state.rs
@@ -49,6 +49,7 @@ use deno_runtime::deno_tls::rustls::RootCertStore;
 use deno_runtime::deno_web::BlobStore;
 use deno_runtime::inspector_server::InspectorServer;
 use deno_runtime::permissions::Permissions;
+use import_map::parse_from_json;
 use import_map::ImportMap;
 use log::warn;
 use std::collections::HashSet;
@@ -617,7 +618,7 @@ pub fn import_map_from_text(
   specifier: &Url,
   json_text: &str,
 ) -> Result<ImportMap, AnyError> {
-  let result = ImportMap::from_json_with_diagnostics(specifier, json_text)?;
+  let result = parse_from_json(specifier, json_text)?;
   if !result.diagnostics.is_empty() {
     warn!(
       "Import map diagnostics:\n{}",
diff --git a/cli/tests/integration/lsp_tests.rs b/cli/tests/integration/lsp_tests.rs
index 7607582c8..d45b90955 100644
--- a/cli/tests/integration/lsp_tests.rs
+++ b/cli/tests/integration/lsp_tests.rs
@@ -548,6 +548,196 @@ fn lsp_import_assertions() {
 }
 
 #[test]
+fn lsp_import_map_import_completions() {
+  let temp_dir = TempDir::new().expect("could not create temp dir");
+  let mut params: lsp::InitializeParams =
+    serde_json::from_value(load_fixture("initialize_params.json")).unwrap();
+  let import_map =
+    serde_json::to_vec_pretty(&load_fixture("import-map-completions.json"))
+      .unwrap();
+  fs::write(temp_dir.path().join("import-map.json"), import_map).unwrap();
+  fs::create_dir(temp_dir.path().join("lib")).unwrap();
+  fs::write(
+    temp_dir.path().join("lib").join("b.ts"),
+    r#"export const b = "b";"#,
+  )
+  .unwrap();
+
+  params.root_uri = Some(Url::from_file_path(temp_dir.path()).unwrap());
+  if let Some(Value::Object(mut map)) = params.initialization_options {
+    map.insert("importMap".to_string(), json!("import-map.json"));
+    params.initialization_options = Some(Value::Object(map));
+  }
+
+  let deno_exe = deno_exe_path();
+  let mut client = LspClient::new(&deno_exe).unwrap();
+  client
+    .write_request::<_, _, Value>("initialize", params)
+    .unwrap();
+
+  client.write_notification("initialized", json!({})).unwrap();
+  let uri = Url::from_file_path(temp_dir.path().join("a.ts")).unwrap();
+
+  did_open(
+    &mut client,
+    json!({
+      "textDocument": {
+        "uri": uri,
+        "languageId": "typescript",
+        "version": 1,
+        "text": "import * as a from \"/~/b.ts\";\nimport * as b from \"\""
+      }
+    }),
+  );
+
+  let (maybe_res, maybe_err) = client
+    .write_request(
+      "textDocument/completion",
+      json!({
+        "textDocument": {
+          "uri": uri
+        },
+        "position": {
+          "line": 1,
+          "character": 20
+        },
+        "context": {
+          "triggerKind": 2,
+          "triggerCharacter": "\""
+        }
+      }),
+    )
+    .unwrap();
+  assert!(maybe_err.is_none());
+  assert_eq!(
+    maybe_res,
+    Some(json!({
+      "isIncomplete": false,
+      "items": [
+        {
+          "label": ".",
+          "kind": 19,
+          "detail": "(local)",
+          "sortText": "1",
+          "insertText": "."
+        },
+        {
+          "label": "..",
+          "kind": 19,
+          "detail": "(local)",
+          "sortText": "1",
+          "insertText": ".."
+        },
+        {
+          "label": "std",
+          "kind": 19,
+          "detail": "(import map)",
+          "sortText": "std",
+          "insertText": "std"
+        },
+        {
+          "label": "fs",
+          "kind": 17,
+          "detail": "(import map)",
+          "sortText": "fs",
+          "insertText": "fs"
+        },
+        {
+          "label": "/~",
+          "kind": 19,
+          "detail": "(import map)",
+          "sortText": "/~",
+          "insertText": "/~"
+        }
+      ]
+    }))
+  );
+
+  client
+    .write_notification(
+      "textDocument/didChange",
+      json!({
+        "textDocument": {
+          "uri": uri,
+          "version": 2
+        },
+        "contentChanges": [
+          {
+            "range": {
+              "start": {
+                "line": 1,
+                "character": 20
+              },
+              "end": {
+                "line": 1,
+                "character": 20
+              }
+            },
+            "text": "/~/"
+          }
+        ]
+      }),
+    )
+    .unwrap();
+  let (method, _) = client.read_notification::<Value>().unwrap();
+  assert_eq!(method, "textDocument/publishDiagnostics");
+  let (method, _) = client.read_notification::<Value>().unwrap();
+  assert_eq!(method, "textDocument/publishDiagnostics");
+  let (method, _) = client.read_notification::<Value>().unwrap();
+  assert_eq!(method, "textDocument/publishDiagnostics");
+
+  let (maybe_res, maybe_err) = client
+    .write_request(
+      "textDocument/completion",
+      json!({
+        "textDocument": {
+          "uri": uri
+        },
+        "position": {
+          "line": 1,
+          "character": 23
+        },
+        "context": {
+          "triggerKind": 2,
+          "triggerCharacter": "/"
+        }
+      }),
+    )
+    .unwrap();
+  assert!(maybe_err.is_none());
+  assert_eq!(
+    maybe_res,
+    Some(json!({
+      "isIncomplete": false,
+      "items": [
+        {
+          "label": "b.ts",
+          "kind": 9,
+          "detail": "(import map)",
+          "sortText": "1",
+          "filterText": "/~/b.ts",
+          "textEdit": {
+            "range": {
+              "start": {
+                "line": 1,
+                "character": 20
+              },
+              "end": {
+                "line": 1,
+                "character": 23
+              }
+            },
+            "newText": "/~/b.ts"
+          }
+        }
+      ]
+    }))
+  );
+
+  shutdown(&mut client);
+}
+
+#[test]
 fn lsp_hover() {
   let mut client = init("initialize_params.json");
   did_open(
diff --git a/cli/tests/testdata/lsp/import-map-completions.json b/cli/tests/testdata/lsp/import-map-completions.json
new file mode 100644
index 000000000..f2275222a
--- /dev/null
+++ b/cli/tests/testdata/lsp/import-map-completions.json
@@ -0,0 +1,7 @@
+{
+  "imports": {
+    "/~/": "./lib/",
+    "fs": "https://example.com/fs/index.js",
+    "std/": "https://example.com/std@0.123.0/"
+  }
+}