fix: fix starlark debugger broken in release 0.11.0 (#432) (#433)

This PR fixes starlark debugging which is broken in release 0.11.0 #432. The debugger program currently fails to start because it can't import vscode. In addition, it also fixes hovering over symbols with starlark debugger respond with errors because symbols are not defined.

scripts/build.sh

@@ -25,14 +25,14 @@ cd "$(dirname "${BASH_SOURCE[0]}")/.." > /dev/null
 # extension's build time.
 if [[ ! -f src/protos/protos.js ]] ; then
   sed -e "s#^#src/protos/#" src/protos/protos_list.txt | \
-      xargs pbjs -t static-module -o src/protos/protos.js
+      xargs npx pbjs -t static-module -o src/protos/protos.js
 fi
 if [[ ! -f src/protos/protos.d.ts ]] ; then
-  pbts -o src/protos/protos.d.ts src/protos/protos.js
+  npx pbts -o src/protos/protos.d.ts src/protos/protos.js
 fi
 
 # Convert yaml language definition to json form requred by vscode.
-js-yaml syntaxes/bazelrc.tmLanguage.yaml > syntaxes/bazelrc.tmLanguage.json
+npx js-yaml syntaxes/bazelrc.tmLanguage.yaml > syntaxes/bazelrc.tmLanguage.json
 
 # Compile the rest of the project.
-tsc "$@" -p ./
+npx tsc "$@" -p ./

src/debug-adapter/client.ts

@@ -15,6 +15,7 @@
 import * as child_process from "child_process";
 import * as fs from "fs";
 import * as path from "path";
+import * as util from "util";
 import {
   ContinuedEvent,
   DebugSession,
@@ -32,7 +33,8 @@ import { DebugProtocol } from "vscode-debugprotocol";
 import { skylark_debugging } from "../protos";
 import { BazelDebugConnection } from "./connection";
 import { Handles } from "./handles";
-import { BazelInfo } from "../bazel/bazel_info";
+
+const execFile = util.promisify(child_process.execFile);
 
 /**
  * Returns a {@code number} equivalent to the given {@code number} or
@@ -165,11 +167,11 @@ class BazelDebugSession extends DebugSession {
   ) {
     const port = args.port || 7300;
     const verbose = args.verbose || false;
+    const bazelStartupOptions: string[] = args.bazelStartupOptions || [];
 
     const bazelExecutable = this.bazelExecutable(args);
-    this.bazelInfo = await new BazelInfo(bazelExecutable, args.cwd).getAll();
-
-    const fullArgs = args.bazelStartupOptions
+    this.bazelInfo = await this.getBazelInfo(bazelExecutable, args.cwd);
+    const fullArgs = bazelStartupOptions
       .concat([
         args.bazelCommand,
         "--color=yes",
@@ -398,32 +400,35 @@ class BazelDebugSession extends DebugSession {
     args: DebugProtocol.EvaluateArguments,
   ) {
     const threadId = this.frameThreadIds.get(args.frameId);
-
-    const value = (
-      await this.bazelConnection.sendRequest({
+    try {
+      const evaluateResponse = await this.bazelConnection.sendRequest({
         evaluate: skylark_debugging.EvaluateRequest.create({
           statement: args.expression,
           threadId,
         }),
-      })
-    ).evaluate.result;
-
-    let valueHandle: number;
-    if (value.hasChildren && value.id) {
-      // Record the value in a handle so that its children can be queried when
-      // the user expands it in the UI. We also record the thread ID for the
-      // value since we need it when we make that request later.
-      valueHandle = this.variableHandles.create(value);
-      this.valueThreadIds.set(valueHandle, threadId);
-    } else {
-      valueHandle = 0;
-    }
+      });
 
-    response.body = {
-      result: value.description,
-      variablesReference: valueHandle,
-    };
-    this.sendResponse(response);
+      const value = evaluateResponse.evaluate.result;
+
+      let valueHandle: number;
+      if (value.hasChildren && value.id) {
+        // Record the value in a handle so that its children can be queried when
+        // the user expands it in the UI. We also record the thread ID for the
+        // value since we need it when we make that request later.
+        valueHandle = this.variableHandles.create(value);
+        this.valueThreadIds.set(valueHandle, threadId);
+      } else {
+        valueHandle = 0;
+      }
+
+      response.body = {
+        result: value.description,
+        variablesReference: valueHandle,
+      };
+      this.sendResponse(response);
+    } catch (e) {
+      this.debugLog(`Unable to evaluate expression: ${args.expression}`);
+    }
   }
 
   // Execution/control flow requests
@@ -532,6 +537,36 @@ class BazelDebugSession extends DebugSession {
     return bazelExecutable;
   }
 
+  /**
+   * Invokes {@code bazel info} and returns the information in a map.
+   *
+   * @param bazelExecutable The name/path of the Bazel executable.
+   * @param cwd The working directory in which Bazel should be launched.
+   */
+  private async getBazelInfo(
+    bazelExecutable: string,
+    cwd: string,
+  ): Promise<Map<string, string>> {
+    const execOptions = {
+      cwd,
+      // The maximum amount of data allowed on stdout. 500KB should be plenty
+      // of `bazel info`, but if this becomes problematic we can switch to the
+      // event-based `child_process` APIs instead.
+      maxBuffer: 500 * 1024,
+    };
+    const { stdout } = await execFile(bazelExecutable, ["info"], execOptions);
+    const keyValues = new Map<string, string>();
+    const lines = stdout.trim().split("\n");
+    for (const line of lines) {
+      // Windows paths can have >1 ':', so can't use line.split(":", 2)
+      const splitterIndex = line.indexOf(":");
+      const key = line.substring(0, splitterIndex);
+      const value = line.substring(splitterIndex + 1);
+      keyValues.set(key.trim(), value.trim());
+    }
+    return keyValues;
+  }
+
   /**
    * Launches the Bazel process to be debugged.
    *