Add get_environment and render_as_load to the LspContext

Summary: Required in future diffs to do auto-insertion of loads and to do completion of globals.

Reviewed By: lmvasquezg

Differential Revision: D47208502

fbshipit-source-id: 68c8cdcccf1515c32738e4412d03d18c2d27df55

Author: ndmitchell

starlark/bin/eval.rs

@@ -30,6 +30,7 @@ use starlark::docs::get_registered_starlark_docs;
 use starlark::docs::render_docs_as_code;
 use starlark::docs::Doc;
 use starlark::docs::DocItem;
+use starlark::docs::DocModule;
 use starlark::environment::FrozenModule;
 use starlark::environment::Globals;
 use starlark::environment::Module;
@@ -352,6 +353,19 @@ impl LspContext for Context {
     ) -> anyhow::Result<Option<LspUrl>> {
         Ok(self.builtin_symbols.get(symbol).cloned())
     }
+
+    fn render_as_load(
+        &self,
+        _target: &LspUrl,
+        _current_file: &LspUrl,
+        _workspace_root: Option<&Path>,
+    ) -> anyhow::Result<String> {
+        Err(anyhow::anyhow!("Not yet implemented, render_as_load"))
+    }
+
+    fn get_environment(&self, _uri: &LspUrl) -> DocModule {
+        DocModule::default()
+    }
 }
 
 pub(crate) fn globals() -> Globals {

starlark/src/lsp/server.rs

@@ -69,6 +69,7 @@ use serde::Serializer;
 
 use crate::codemap::ResolvedSpan;
 use crate::codemap::Span;
+use crate::docs::DocModule;
 use crate::lsp::definition::Definition;
 use crate::lsp::definition::DottedDefinition;
 use crate::lsp::definition::IdentifierDefinition;
@@ -272,7 +273,19 @@ pub trait LspContext {
         workspace_root: Option<&Path>,
     ) -> anyhow::Result<LspUrl>;
 
-    /// Resolve a string literal into a Url and a function that specifies a locaction within that
+    /// Render the target URL to use as a path in a `load()` statement. If `target` is
+    /// in the same package as `current_file`, the result is a relative path.
+    ///
+    /// `target` is the file that should be loaded by `load()`.
+    /// `current_file` is the file that the `load()` statement will be inserted into.
+    fn render_as_load(
+        &self,
+        target: &LspUrl,
+        current_file: &LspUrl,
+        workspace_root: Option<&Path>,
+    ) -> anyhow::Result<String>;
+
+    /// Resolve a string literal into a Url and a function that specifies a location within that
     /// target file.
     ///
     /// This can be used for things like file paths in string literals, build targets, etc.
@@ -296,6 +309,9 @@ pub trait LspContext {
         Ok(result)
     }
 
+    /// Get the preloaded environment for a particular file.
+    fn get_environment(&self, uri: &LspUrl) -> DocModule;
+
     /// Get the LSPUrl for a global symbol if possible.
     ///
     /// The current file is provided in case different files have different global symbols

starlark/src/lsp/test.rs

@@ -61,6 +61,8 @@ use crate::docs::render_docs_as_code;
 use crate::docs::Doc;
 use crate::docs::DocFunction;
 use crate::docs::DocItem;
+use crate::docs::DocMember;
+use crate::docs::DocModule;
 use crate::docs::Identifier;
 use crate::docs::Location;
 use crate::errors::EvalMessage;
@@ -95,6 +97,14 @@ enum ResolveLoadError {
     WrongScheme(String, LspUrl),
 }
 
+#[derive(thiserror::Error, Debug)]
+enum RenderLoadError {
+    #[error("Path `{}` provided, which does not seem to contain a filename", .0.display())]
+    MissingTargetFilename(PathBuf),
+    #[error("Urls `{}` and `{}` was expected to be of type `{}`", .1, .2, .0)]
+    WrongScheme(String, LspUrl, LspUrl),
+}
+
 #[derive(thiserror::Error, Debug)]
 pub(crate) enum TestServerError {
     #[error("Attempted to set the contents of a file with a non-absolute path `{}`", .0.display())]
@@ -170,6 +180,51 @@ impl LspContext for TestServerContext {
         }
     }
 
+    fn render_as_load(
+        &self,
+        target: &LspUrl,
+        current_file: &LspUrl,
+        workspace_root: Option<&Path>,
+    ) -> anyhow::Result<String> {
+        match (target, current_file) {
+            (LspUrl::File(target_path), LspUrl::File(current_file_path)) => {
+                let target_package = target_path.parent();
+                let current_file_package = current_file_path.parent();
+                let target_filename = target_path.file_name();
+
+                // If both are in the same package, return a relative path.
+                if matches!((target_package, current_file_package), (Some(a), Some(b)) if a == b) {
+                    return match target_filename {
+                        Some(filename) => Ok(format!(":{}", filename.to_string_lossy())),
+                        None => {
+                            Err(RenderLoadError::MissingTargetFilename(target_path.clone()).into())
+                        }
+                    };
+                }
+
+                let target_path = workspace_root
+                    .and_then(|root| target_path.strip_prefix(root).ok())
+                    .unwrap_or(target_path);
+
+                Ok(format!(
+                    "//{}:{}",
+                    target_package
+                        .map(|path| path.to_string_lossy())
+                        .unwrap_or_default(),
+                    target_filename
+                        .unwrap_or(target_path.as_os_str())
+                        .to_string_lossy()
+                ))
+            }
+            _ => Err(RenderLoadError::WrongScheme(
+                "file://".to_owned(),
+                target.clone(),
+                current_file.clone(),
+            )
+            .into()),
+        }
+    }
+
     fn resolve_string_literal(
         &self,
         literal: &str,
@@ -228,6 +283,17 @@ impl LspContext for TestServerContext {
     ) -> anyhow::Result<Option<LspUrl>> {
         Ok(self.builtin_symbols.get(symbol).cloned())
     }
+
+    fn get_environment(&self, _uri: &LspUrl) -> DocModule {
+        DocModule {
+            docs: None,
+            members: self
+                .builtin_symbols
+                .keys()
+                .map(|name| (name.clone(), DocMember::Function(DocFunction::default())))
+                .collect(),
+        }
+    }
 }
 
 /// A server for use in testing that provides helpers for sending requests, correlating