10.8.0 breaks Java/Go transliteration for downstream jsii-rosetta consumers

[jsteinich]

What happened

10.8.0 changed jsii.tsc: { outDir: "lib", rootDir: "src" } to jsii.tsconfig + validateTsconfig in package.json. That drops jsii.tsc.outDir, which downstream consumers need in order to map the shipped lib/*.d.ts paths back to the src/... symbol ids recorded in the assembly.

The consequence is that any tool transliterating TypeScript that imports constructs now emits incorrect Java and Go imports:

language	expected	actual on 10.8.0
Java	import software.constructs.Construct;	import constructs.Construct;
Go	"github.com/aws/constructs-go/constructs"	"github.com/aws-samples/dummy/constructs"

Python and C# are unaffected, but only coincidentally — rosetta's fallback name derivation (constructs, Constructs) happens to match the correct target names for those two languages.

The failure is silent: the assembly loads fine and the lookup just degrades to "not a jsii symbol", so the output looks plausible.

Reproduction

mkdir repro && cd repro && npm init -y
npm install jsii-rosetta@6.0.7 constructs@10.8.0

cat > snippet.ts <<'EOF'
import { Construct } from "constructs";
export class Foo extends Construct {
  constructor(scope: Construct, id: string) { super(scope, id); }
}
EOF

cat > run.js <<'EOF'
const rosetta = require("jsii-rosetta");
const fs = require("fs"), path = require("path");
const file = {
  contents: fs.readFileSync(path.join(__dirname, "snippet.ts"), "utf8"),
  fileName: path.join(__dirname, "snippet.ts"),
};
console.log("constructs", require("constructs/package.json").version);
for (const [name, V] of [["java", rosetta.JavaVisitor], ["go", rosetta.GoVisitor]]) {
  const { translation } = rosetta.translateTypeScript(file, new V(), {});
  console.log(" ", name.padEnd(4), "->", translation.split("\n").find((l) => /constructs/i.test(l)).trim());
}
EOF

node run.js
npm install constructs@10.7.2 && node run.js

10.7.2 is correct; 10.8.0 is not. Patching jsii.tsc back into the installed 10.8.0 package.json restores correct output with nothing else changed, which isolates it to this field.

Reproduced on both jsii-rosetta@5.9.39 and jsii-rosetta@6.0.7, so it is not resolved by consumers upgrading to the jsii 6.x toolchain.

Note

The underlying gap is in jsii itself: symbolIdentifier() falls back to assembly.metadata.tscRootDir when jsii.tsc.rootDir is absent, but has no equivalent fallback for outDir, and tsconfig.json is not published in the npm tarball. I have filed that separately as aws/jsii-compiler#2740.

Raising it here as well since constructs is likely the most widely consumed package to adopt jsii.tsconfig, and it may be worth restoring jsii.tsc.outDir/rootDir in a patch release until the jsii-side fix ships.

Environment

• constructs 10.8.0 (broken) vs 10.7.2 (fine)
• jsii-rosetta 6.0.7 / jsii 6.0.7, also 5.9.39 / 5.9.x
• Node.js v22.22.2

[mrgrain]

Thanks for the report! Deprecated 10.8.0 for now. Working on a compiler fix and will then release constructs with jsii.tsc.outDir.
There's also going to be a fix in jsii-rosetta I think.

[mrgrain]

10.8.1 released and should work with existing rosetta versions. But we also have new versions of jsii-rosetta out to address the issue better. Plus jsii-complier now has the proposed fix.

[mrgrain]

@jsteinich Let me know if this solves it for you!