fix(esbuild): set correct base url when rule is at root (#2506)

Author: mattem

examples/esbuild/package-lock.json

@@ -7,6 +7,9 @@
         "tslib": "1.9.0",
         "typescript": "3.5.3"
     },
+    "dependencies": {
+        "chalk": "4.1.0"
+    },
     "scripts": {
         "test": "bazel test //..."
     }

examples/esbuild/package.json

@@ -9,7 +9,14 @@ ts_project(
         "main.ts",
         "name.ts",
     ],
-    tsconfig = {},
+    tsconfig = {
+        "compilerOptions": {
+            "esModuleInterop": True,
+        },
+    },
+    deps = [
+        "@npm//chalk",
+    ],
 )
 
 # create a single bundle of the JS sources

examples/esbuild/src/BUILD.bazel

@@ -1,8 +1,10 @@
+import chalk from 'chalk';
+
 import {NAME} from './name';
 
 export function greeting(name: string): string {
-  return `Hello ${name}!`;
+  return `Hello ${chalk.bold(name)}!`;
 }
 
-const sentance = greeting(NAME);
-console.log(sentance);
+const sentence = greeting(NAME);
+console.log(sentence);

examples/esbuild/src/main.ts

@@ -82,6 +82,8 @@ def write_jsconfig_file(ctx, path_alias_mappings):
         ctx: The rule context
         path_alias_mappings: Dict with the mappings
 
+    Returns:
+        File object reference for the jsconfig file
     """
 
     # The package path
@@ -90,7 +92,10 @@ def write_jsconfig_file(ctx, path_alias_mappings):
     # Replace all segments in the path with .. join them with "/" and postfix
     # it with another / to get a relative path from the build file dir
     # to the workspace root.
-    base_url_path = "/".join([".." for segment in rule_path.split("/")]) + "/"
+    if len(rule_path) == 0:
+        base_url_path = "."
+    else:
+        base_url_path = "/".join([".." for segment in rule_path.split("/")]) + "/"
 
     # declare the jsconfig_file
     jsconfig_file = ctx.actions.declare_file("%s.config.json" % ctx.attr.name)