1 files changed, 315 insertions, 0 deletions
diff --git a/cli/lsp/documents.rs b/cli/lsp/documents.rs
new file mode 100644
index 000000000..2f355c4d9
--- /dev/null
+++ b/cli/lsp/documents.rs
@@ -0,0 +1,315 @@
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+
+use super::analysis;
+use super::text::LineIndex;
+
+use crate::import_map::ImportMap;
+use crate::media_type::MediaType;
+
+use deno_core::error::custom_error;
+use deno_core::error::AnyError;
+use deno_core::error::Context;
+use deno_core::ModuleSpecifier;
+use lspower::lsp_types::TextDocumentContentChangeEvent;
+use std::collections::HashMap;
+use std::ops::Range;
+
+#[derive(Debug, PartialEq, Eq)]
+enum IndexValid {
+  All,
+  UpTo(u32),
+}
+
+impl IndexValid {
+  fn covers(&self, line: u32) -> bool {
+    match *self {
+      IndexValid::UpTo(to) => to > line,
+      IndexValid::All => true,
+    }
+  }
+}
+
+#[derive(Debug, Clone, Default)]
+pub struct DocumentData {
+  bytes: Option<Vec<u8>>,
+  line_index: Option<LineIndex>,
+  dependencies: Option<HashMap<String, analysis::Dependency>>,
+  version: Option<i32>,
+}
+
+impl DocumentData {
+  pub fn apply_content_changes(
+    &mut self,
+    content_changes: Vec<TextDocumentContentChangeEvent>,
+  ) -> Result<(), AnyError> {
+    if self.bytes.is_none() {
+      return Ok(());
+    }
+    let content = &mut String::from_utf8(self.bytes.clone().unwrap())
+      .context("unable to parse bytes to string")?;
+    let mut line_index = if let Some(line_index) = &self.line_index {
+      line_index.clone()
+    } else {
+      LineIndex::new(&content)
+    };
+    let mut index_valid = IndexValid::All;
+    for change in content_changes {
+      if let Some(range) = change.range {
+        if !index_valid.covers(range.start.line) {
+          line_index = LineIndex::new(&content);
+        }
+        index_valid = IndexValid::UpTo(range.start.line);
+        let range = line_index.get_text_range(range)?;
+        content.replace_range(Range::<usize>::from(range), &change.text);
+      } else {
+        *content = change.text;
+        index_valid = IndexValid::UpTo(0);
+      }
+    }
+    self.bytes = Some(content.as_bytes().to_owned());
+    self.line_index = if index_valid == IndexValid::All {
+      Some(line_index)
+    } else {
+      Some(LineIndex::new(&content))
+    };
+    Ok(())
+  }
+
+  pub fn content(&self) -> Result<Option<String>, AnyError> {
+    if let Some(bytes) = self.bytes.clone() {
+      Ok(Some(
+        String::from_utf8(bytes).context("cannot decode bytes to string")?,
+      ))
+    } else {
+      Ok(None)
+    }
+  }
+}
+
+#[derive(Debug, Clone, Default)]
+pub struct DocumentCache {
+  docs: HashMap<ModuleSpecifier, DocumentData>,
+}
+
+impl DocumentCache {
+  pub fn analyze_dependencies(
+    &mut self,
+    specifier: &ModuleSpecifier,
+    maybe_import_map: &Option<ImportMap>,
+  ) -> Result<(), AnyError> {
+    if !self.contains(specifier) {
+      return Err(custom_error(
+        "NotFound",
+        format!(
+          "The specifier (\"{}\") does not exist in the document cache.",
+          specifier
+        ),
+      ));
+    }
+
+    let doc = self.docs.get_mut(specifier).unwrap();
+    if let Some(source) = &doc.content()? {
+      if let Some((dependencies, _)) = analysis::analyze_dependencies(
+        specifier,
+        source,
+        &MediaType::from(specifier),
+        maybe_import_map,
+      ) {
+        doc.dependencies = Some(dependencies);
+      } else {
+        doc.dependencies = None;
+      }
+    } else {
+      doc.dependencies = None;
+    }
+
+    Ok(())
+  }
+
+  pub fn change(
+    &mut self,
+    specifier: &ModuleSpecifier,
+    version: i32,
+    content_changes: Vec<TextDocumentContentChangeEvent>,
+  ) -> Result<(), AnyError> {
+    if !self.contains(specifier) {
+      return Err(custom_error(
+        "NotFound",
+        format!(
+          "The specifier (\"{}\") does not exist in the document cache.",
+          specifier
+        ),
+      ));
+    }
+
+    let doc = self.docs.get_mut(specifier).unwrap();
+    doc.apply_content_changes(content_changes)?;
+    doc.version = Some(version);
+    Ok(())
+  }
+
+  pub fn close(&mut self, specifier: &ModuleSpecifier) {
+    if let Some(mut doc) = self.docs.get_mut(specifier) {
+      doc.version = None;
+      doc.dependencies = None;
+    }
+  }
+
+  pub fn contains(&self, specifier: &ModuleSpecifier) -> bool {
+    self.docs.contains_key(specifier)
+  }
+
+  pub fn content(
+    &self,
+    specifier: &ModuleSpecifier,
+  ) -> Result<Option<String>, AnyError> {
+    if let Some(doc) = self.docs.get(specifier) {
+      doc.content()
+    } else {
+      Ok(None)
+    }
+  }
+
+  pub fn dependencies(
+    &self,
+    specifier: &ModuleSpecifier,
+  ) -> Option<HashMap<String, analysis::Dependency>> {
+    let doc = self.docs.get(specifier)?;
+    doc.dependencies.clone()
+  }
+
+  pub fn len(&self) -> usize {
+    self.docs.iter().count()
+  }
+
+  pub fn line_index(&self, specifier: &ModuleSpecifier) -> Option<LineIndex> {
+    let doc = self.docs.get(specifier)?;
+    doc.line_index.clone()
+  }
+
+  pub fn open(
+    &mut self,
+    specifier: ModuleSpecifier,
+    version: i32,
+    text: String,
+  ) {
+    self.docs.insert(
+      specifier,
+      DocumentData {
+        bytes: Some(text.as_bytes().to_owned()),
+        version: Some(version),
+        line_index: Some(LineIndex::new(&text)),
+        ..Default::default()
+      },
+    );
+  }
+
+  pub fn open_specifiers(&self) -> Vec<&ModuleSpecifier> {
+    self
+      .docs
+      .iter()
+      .filter_map(|(key, data)| {
+        if data.version.is_some() {
+          Some(key)
+        } else {
+          None
+        }
+      })
+      .collect()
+  }
+
+  pub fn version(&self, specifier: &ModuleSpecifier) -> Option<i32> {
+    self.docs.get(specifier).and_then(|doc| doc.version)
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+  use lspower::lsp_types;
+
+  #[test]
+  fn test_document_cache_contains() {
+    let mut document_cache = DocumentCache::default();
+    let specifier = ModuleSpecifier::resolve_url("file:///a/b.ts").unwrap();
+    let missing_specifier =
+      ModuleSpecifier::resolve_url("file:///a/c.ts").unwrap();
+    document_cache.open(
+      specifier.clone(),
+      1,
+      "console.log(\"Hello Deno\");\n".to_owned(),
+    );
+    assert!(document_cache.contains(&specifier));
+    assert!(!document_cache.contains(&missing_specifier));
+  }
+
+  #[test]
+  fn test_document_cache_change() {
+    let mut document_cache = DocumentCache::default();
+    let specifier = ModuleSpecifier::resolve_url("file:///a/b.ts").unwrap();
+    document_cache.open(
+      specifier.clone(),
+      1,
+      "console.log(\"Hello deno\");\n".to_owned(),
+    );
+    document_cache
+      .change(
+        &specifier,
+        2,
+        vec![lsp_types::TextDocumentContentChangeEvent {
+          range: Some(lsp_types::Range {
+            start: lsp_types::Position {
+              line: 0,
+              character: 19,
+            },
+            end: lsp_types::Position {
+              line: 0,
+              character: 20,
+            },
+          }),
+          range_length: Some(1),
+          text: "D".to_string(),
+        }],
+      )
+      .expect("failed to make changes");
+    let actual = document_cache
+      .content(&specifier)
+      .expect("failed to get content");
+    assert_eq!(actual, Some("console.log(\"Hello Deno\");\n".to_string()));
+  }
+
+  #[test]
+  fn test_document_cache_change_utf16() {
+    let mut document_cache = DocumentCache::default();
+    let specifier = ModuleSpecifier::resolve_url("file:///a/b.ts").unwrap();
+    document_cache.open(
+      specifier.clone(),
+      1,
+      "console.log(\"Hello 🦕\");\n".to_owned(),
+    );
+    document_cache
+      .change(
+        &specifier,
+        2,
+        vec![lsp_types::TextDocumentContentChangeEvent {
+          range: Some(lsp_types::Range {
+            start: lsp_types::Position {
+              line: 0,
+              character: 19,
+            },
+            end: lsp_types::Position {
+              line: 0,
+              character: 21,
+            },
+          }),
+          range_length: Some(2),
+          text: "Deno".to_string(),
+        }],
+      )
+      .expect("failed to make changes");
+    let actual = document_cache
+      .content(&specifier)
+      .expect("failed to get content");
+    assert_eq!(actual, Some("console.log(\"Hello Deno\");\n".to_string()));
+  }
+}