Jtd to esm validator

.github/workflows/ci.yml

@@ -39,8 +39,8 @@ jobs:
                       for k in totals: totals[k]+=int(r.get(k,'0'))
                   except Exception:
                       pass
-          exp_tests=611
-          exp_skipped=0
+          exp_tests=639
+          exp_skipped=5
           if totals['tests']!=exp_tests or totals['skipped']!=exp_skipped:
               print(f"Unexpected test totals: {totals} != expected tests={exp_tests}, skipped={exp_skipped}")
               sys.exit(1)

.github/workflows/jtd-esm-codegen-release.yml

@@ -0,0 +1,142 @@
+name: JTD-ESM-Codegen Nightly
+
+on:
+  schedule:
+    - cron: '0 3 * * *'  # 3 AM UTC daily
+  workflow_dispatch:
+
+permissions:
+  contents: write
+
+jobs:
+  build-uber-jar:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: '21'
+          cache: 'maven'
+      - name: Build uber JAR
+        run: |
+          ./mvnw -pl jtd-esm-codegen -am package
+          cp jtd-esm-codegen/target/jtd-esm-codegen.jar jtd-esm-codegen.jar
+      - uses: actions/upload-artifact@v4
+        with:
+          name: uber-jar
+          path: jtd-esm-codegen.jar
+
+  native-linux:
+    needs: build-uber-jar
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: uber-jar
+          path: .
+      - uses: graalvm/setup-graalvm@v1
+        with:
+          java-version: '21'
+          distribution: 'graalvm'
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          components: 'native-image'
+          cache: 'maven'
+      - name: Build native image
+        run: |
+          native-image --no-fallback -jar jtd-esm-codegen.jar jtd-esm-codegen-linux-amd64
+          chmod +x jtd-esm-codegen-linux-amd64
+      - uses: actions/upload-artifact@v4
+        with:
+          name: native-linux-amd64
+          path: jtd-esm-codegen-linux-amd64
+
+  native-windows:
+    needs: build-uber-jar
+    runs-on: windows-latest
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: uber-jar
+          path: .
+      - uses: graalvm/setup-graalvm@v1
+        with:
+          java-version: '21'
+          distribution: 'graalvm'
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          components: 'native-image'
+          cache: 'maven'
+      - name: Build native image
+        run: |
+          native-image --no-fallback -jar jtd-esm-codegen.jar jtd-esm-codegen-windows-amd64
+      - uses: actions/upload-artifact@v4
+        with:
+          name: native-windows-amd64
+          path: jtd-esm-codegen-windows-amd64.exe
+
+  native-macos-intel:
+    needs: build-uber-jar
+    runs-on: macos-13  # Intel
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: uber-jar
+          path: .
+      - uses: graalvm/setup-graalvm@v1
+        with:
+          java-version: '21'
+          distribution: 'graalvm'
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          components: 'native-image'
+          cache: 'maven'
+      - name: Build native image
+        run: |
+          native-image --no-fallback -jar jtd-esm-codegen.jar jtd-esm-codegen-macos-amd64
+          chmod +x jtd-esm-codegen-macos-amd64
+      - uses: actions/upload-artifact@v4
+        with:
+          name: native-macos-amd64
+          path: jtd-esm-codegen-macos-amd64
+
+  native-macos-arm:
+    needs: build-uber-jar
+    runs-on: macos-14  # Apple Silicon
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: uber-jar
+          path: .
+      - uses: graalvm/setup-graalvm@v1
+        with:
+          java-version: '21'
+          distribution: 'graalvm'
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          components: 'native-image'
+          cache: 'maven'
+      - name: Build native image
+        run: |
+          native-image --no-fallback -jar jtd-esm-codegen.jar jtd-esm-codegen-macos-arm64
+          chmod +x jtd-esm-codegen-macos-arm64
+      - uses: actions/upload-artifact@v4
+        with:
+          name: native-macos-arm64
+          path: jtd-esm-codegen-macos-arm64
+
+  release:
+    needs: [native-linux, native-windows, native-macos-intel, native-macos-arm]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/download-artifact@v4
+      - name: Create nightly release
+        uses: softprops/action-gh-release@v1
+        with:
+          tag_name: nightly-${{ github.run_number }}
+          name: Nightly Build ${{ github.run_number }}
+          prerelease: true
+          files: |
+            native-linux-amd64/jtd-esm-codegen-linux-amd64
+            native-windows-amd64/jtd-esm-codegen-windows-amd64.exe
+            native-macos-amd64/jtd-esm-codegen-macos-amd64
+            native-macos-arm64/jtd-esm-codegen-macos-arm64
+            uber-jar/jtd-esm-codegen.jar
+

README.md

@@ -15,6 +15,7 @@ In addition to the core backport, this repo includes implementations of more adv
 | --- | --- | --- |
 | `json-java21-jtd` | JSON Type Definition (JTD) validator implementing RFC 8927 | [JTD validator](#json-type-definition-jtd-validator) |
 | `json-java21-jsonpath` | JsonPath query engine over `java.util.json` values | [JsonPath](#jsonpath) |
+| `jtd-esm-codegen` | Experimental JTD → ES2020 ESM validator code generator | [JTD → ESM codegen](#jtd-to-esm-validator-codegen-experimental) |
 
 We welcome contributions to these incubating modules.
 
@@ -388,6 +389,38 @@ Features:
 - ✅ Discriminator tag exemption from additional properties
 - ✅ Stack-based validation preventing StackOverflowError
 
+## JTD to ESM Validator Codegen (Experimental)
+
+This repo also contains an **experimental** CLI tool that reads a JTD schema (RFC 8927) and generates a **vanilla ES2020 module** exporting a `validate(instance)` function. The intended use case is validating JSON event payloads in the browser (for example, across tabs using `BroadcastChannel`) without a build step.
+
+### Supported JTD subset (flat schemas only)
+
+This tool deliberately supports only:
+- `properties` (required properties)
+- `optionalProperties`
+- `type` primitives (`string`, `boolean`, `timestamp`, `int8`, `int16`, `int32`, `uint8`, `uint16`, `uint32`, `float32`, `float64`)
+- `enum`
+- `metadata.id` (used for the output filename prefix)
+
+It rejects other JTD features (`elements`, `values`, `discriminator`/`mapping`, `ref`/`definitions`) and also rejects **nested `properties`** (object schemas inside properties).
+
+When rejected, the error message is:
+
+`Unsupported JTD feature: <feature>. This experimental tool only supports flat schemas with properties, optionalProperties, type, and enum.`
+
+### Build and run
+
+```bash
+./mvnw -pl jtd-esm-codegen -am package
+java -jar ./jtd-esm-codegen/target/jtd-esm-codegen.jar schema.jtd.json
+```
+
+The output file is written to the current directory as:
+
+`<metadata.id>-<sha256_prefix_8>.js`
+
+Where `<sha256_prefix_8>` is the first 8 characters of the SHA-256 hash of the input schema file bytes.
+
 ## Building
 
 Requires JDK 21 or later. Build with Maven: