Add incremental-typespec WF

.github/workflows/arm-incremental-typespec-preview.yaml

@@ -0,0 +1,35 @@
+name: ARM Incremental Typespec (Preview)
+
+on: pull_request
+
+permissions:
+  contents: read
+
+jobs:
+  arm-incremental-typespec-preview:
+    name: ARM Incremental Typespec (Preview)
+
+    runs-on: ubuntu-24.04
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          # Required to detect changed files in PR
+          fetch-depth: 2
+
+      # Output is "none" for no-op, "add" to add label, and "remove" to remove label
+      - id: incremental-typespec
+        name: ARM Incremental Typespec (Preview)
+        uses: actions/github-script@v7
+        with:
+          result-encoding: string
+          script: |
+            const { default: incrementalTypespec } =
+              await import('${{ github.workspace }}/.github/workflows/src/arm-incremental-typespec-preview.js');
+            return await incrementalTypespec({ github, context, core });
+
+      - name: Upload artifact with results
+        uses: ./.github/actions/add-empty-artifact
+        with:
+          name: "incremental-typespec"
+          value: ${{ steps.incremental-typespec.outputs.result }}

.github/workflows/src/arm-incremental-typespec-preview.js

@@ -0,0 +1,99 @@
+// @ts-check
+
+import { readFile } from "fs/promises";
+import { dirname, join } from "path";
+import { getChangedResourceManagerSwaggerFiles } from "./changed-files.js";
+import { lsTree, show } from "./git.js";
+
+/**
+ * @param {import('github-script').AsyncFunctionArguments} AsyncFunctionArguments
+ * @returns {Promise<boolean>}
+ */
+export default async function incrementalTypespec({ github, context, core }) {
+  const changedRmSwaggerFiles = await getChangedResourceManagerSwaggerFiles(
+    core,
+    "HEAD^",
+    "HEAD",
+    "",
+  );
+
+  if (changedRmSwaggerFiles.length == 0) {
+    core.info(
+      "No changes to swagger files containing path '/resource-manager/'",
+    );
+    return false;
+  }
+
+  // If any changed file is not typespec-generated, return false
+  for (const file of changedRmSwaggerFiles) {
+    const swagger = await readFile(
+      join(process.env.GITHUB_WORKSPACE || "", file),
+      { encoding: "utf8" },
+    );
+
+    const swaggerObj = JSON.parse(swagger);
+
+    if (!swaggerObj["info"]?.["x-typespec-generated"]) {
+      core.info(`File "${file}" does not contain "info.x-typespec-generated"`);
+      return false;
+    }
+  }
+
+  const changedSpecDirs = new Set(
+    changedRmSwaggerFiles.map((f) => dirname(dirname(dirname(f)))),
+  );
+
+  // Ensure that each changed spec dir contained at least one typespec-generated swagger in the base commitish
+  for (const changedSpecDir of changedSpecDirs) {
+    // TODO: Create helper to list RM specs in a given commitish
+    const specFilesBaseBranch = await lsTree(
+      "HEAD^",
+      changedSpecDir,
+      core,
+      "-r --name-only",
+    );
+
+    // Filter files to only include RM *.json files
+    const specRmSwaggerFilesBaseBranch = specFilesBaseBranch
+      .split("\n")
+      .filter(
+        (file) =>
+          file.includes("/resource-manager/") &&
+          !file.includes("/examples/") &&
+          file.endsWith(".json"),
+      );
+
+    if (specRmSwaggerFilesBaseBranch.length === 0) {
+      core.info(
+        `Spec folder '${changedSpecDir}' in base branch does not exist or contains no swagger files`,
+      );
+      return false;
+    }
+
+    let containsTypespecGeneratedSwagger = false;
+    // TODO: Add lint rule to prevent using "for...in" instead of "for...of"
+    for (const file of specRmSwaggerFilesBaseBranch) {
+      const baseSwagger = await show("HEAD^", file, core);
+      const baseSwaggerObj = JSON.parse(baseSwagger);
+      if (baseSwaggerObj["info"]?.["x-typespec-generated"]) {
+        core.info(
+          `Spec folder '${changedSpecDir}' in base branch contains typespec-generated swagger: '${file}'`,
+        );
+        containsTypespecGeneratedSwagger = true;
+        continue;
+      }
+    }
+
+    if (!containsTypespecGeneratedSwagger) {
+      core.info(
+        `Spec folder '${changedSpecDir}' in base branch does not contain any typespec-generated swagger.  PR may be a TypeSpec conversion.`,
+      );
+      return false;
+    }
+  }
+
+  core.info(
+    "Appears to contain only incremental changes to existing TypeSpec RP(s)",
+  );
+  return true;
+}