Sourcemaps is broken after v3 upgrade

[mitul45]

🐞 bug report

Affected Rule

The issue is caused by the rule: nodejs_binary

Is this a regression?

Yes, the previous version in which this bug was not present was: 2.3.1

Description

After upgrading the rules_nodejs from 2.3.1 to 3.2.2 the sourcemaps have stopped working. In case the program is throwing an error,

Before:

Error: here
    at Object.<anonymous> (index.ts:1:7)

After:

throw new Error("here");
^

Error: here
    at Object.<anonymous> (/private/var/tmp/_bazel_mshah/fa060aa929cca939406f1ed94045b096/execroot/example/bazel-out/darwin-fastbuild/bin/bin.sh.runfiles/example/index.js:2:7)

As you can see, before this upgrade, the file name displayed in logs is a .ts file and it points to original source, but after the upgrade, the logs contain reference to the compiled .js file.

🔬 Minimal Reproduction

Link to repo: https://github.com/mitul45/bazel-example

To see actual stack-trace, uncomment lines to use rules_nodejs v2.3.1 and downgrade @bazel/typescript to 2.3.1 (yarn upgrade @bazel/[email protected])

🌍 Your Environment

Operating System:

  
macOS Catalina
10.15.7
  

Output of bazel version:

  
/git/bazel-example (main)  >> yarn bazel version
yarn run v1.22.5
$ /Users/mshah/git/bazel-example/node_modules/.bin/bazel version
Bazelisk version: v1.7.5
Build label: 4.0.0
Build target: bazel-out/darwin-opt/bin/src/main/java/com/google/devtools/build/lib/bazel/BazelServer_deploy.jar
Build time: Thu Jan 21 07:38:50 2021 (1611214730)
Build timestamp: 1611214730
Build timestamp as int: 1611214730
✨  Done in 1.39s.
  

Rules_nodejs version:

(Please check that you have matching versions between WORKSPACE file and @bazel/* npm packages.)

  
3.2.2
  

Anything else relevant?
Nope

[joeljeske]

Looks like it could be related to this comment?

#2448 (comment)

Can you try passing that flag to see if it fixes it? Then the real fix is to do as @alexeagle suggested; fix the source maps even without that flag.

[mitul45]

Thanks @joeljeske, adding

        templated_args = [
            "--bazel_patch_module_resolver",
        ],

to bin rule fixed the sourcemaps for me! Do you know how can I use --require source-map-support instead?

[alexeagle]

adding this made the stack trace show .ts files

templated_args = ["--node_options=--require=source-map-support/register"]

diff --git a/BUILD.bazel b/BUILD.bazel
index e922e53..d5bc55c 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -11,5 +11,6 @@ ts_library(
 nodejs_binary(
     name = "bin",
     data = [":sources"],
-    entry_point = ":index.ts"
+    entry_point = ":index.ts",
+    templated_args = ["--node_options=--require=source-map-support/register"],
 )

Note that we vendored a copy of the source-map-support into the rules_nodejs "built-in" distribution, so this is always available to add even if your app doesn't depend on source-map-support itself.

Perhaps we can just always turn this on, like we did in the case of the patched module resolver, I'll TAL