Add function to read the analysis category from a workflow

src/workflow.test.ts

@@ -6,6 +6,7 @@ import {
   CodedError,
   formatWorkflowCause,
   formatWorkflowErrors,
+  getCategoryInput,
   getWorkflowErrors,
   patternIsSuperset,
   Workflow,
@@ -522,3 +523,93 @@ test("getWorkflowErrors() should not report an error if PRs are totally unconfig
     )
   );
 });
+
+test("getCategoryInput returns category for simple workflow with category", (t) => {
+  t.is(
+    getCategoryInput(
+      yaml.load(`
+        jobs:
+          analysis:
+            runs-on: ubuntu-latest
+            steps:
+              - uses: actions/checkout@v2
+              - uses: github/codeql-action/init@v2
+              - uses: github/codeql-action/analyze@v2
+                with:
+                  category: some-category
+    `) as Workflow
+    ),
+    "some-category"
+  );
+});
+
+test("getCategoryInput returns undefined for simple workflow without category", (t) => {
+  t.is(
+    getCategoryInput(
+      yaml.load(`
+        jobs:
+          analysis:
+            runs-on: ubuntu-latest
+            steps:
+              - uses: actions/checkout@v2
+              - uses: github/codeql-action/init@v2
+              - uses: github/codeql-action/analyze@v2
+    `) as Workflow
+    ),
+    undefined
+  );
+});
+
+test("getCategoryInput throws error for workflow with dynamic category", (t) => {
+  t.throws(
+    () =>
+      getCategoryInput(
+        yaml.load(`
+          jobs:
+            analysis:
+              runs-on: ubuntu-latest
+              strategy:
+                matrix:
+                  language: [javascript, python]
+              steps:
+                - uses: actions/checkout@v2
+                - uses: github/codeql-action/init@v2
+                  with:
+                    language: \${{ matrix.language }}
+                - uses: github/codeql-action/analyze@v2
+                  with:
+                    category: "/language:\${{ matrix.language }}"
+    `) as Workflow
+      ),
+    {
+      message:
+        "Could not get category input since it contained a dynamic value.",
+    }
+  );
+});
+
+test("getCategoryInput throws error for workflow with multiple categories", (t) => {
+  t.throws(
+    () =>
+      getCategoryInput(
+        yaml.load(`
+          jobs:
+            analysis:
+              runs-on: ubuntu-latest
+              steps:
+                - uses: actions/checkout@v2
+                - uses: github/codeql-action/init@v2
+                - uses: github/codeql-action/analyze@v2
+                  with:
+                    category: some-category
+                - uses: github/codeql-action/analyze@v2
+                  with:
+                    category: another-category
+      `) as Workflow
+      ),
+    {
+      message:
+        "Could not get category input since multiple categories were specified by the analysis step.",
+    }
+  );
+});

src/workflow.ts

@@ -9,6 +9,8 @@ import { getRequiredEnvParam } from "./util";
 
 interface WorkflowJobStep {
   run: any;
+  uses?: string;
+  with?: { [key: string]: string };
 }
 
 interface WorkflowJob {
@@ -290,3 +292,43 @@ export function getWorkflowRunID(): number {
   }
   return workflowRunID;
 }
+
+export function getAnalyzeSteps(job: WorkflowJob): WorkflowJobStep[] {
+  const steps = job.steps;
+  if (!Array.isArray(steps)) {
+    throw new Error(
+      "Could not get analyze steps since job.steps was not an array."
+    );
+  }
+  return steps.filter((step) =>
+    step.uses?.includes("github/codeql-action/analyze")
+  );
+}
+
+export function getCategoryInput(workflow: Workflow): string | undefined {
+  if (!workflow.jobs) {
+    throw new Error(
+      "Could not get category input since workflow.jobs was undefined."
+    );
+  }
+  const categories: string[] = Object.values(workflow.jobs)
+    .map((job) => getAnalyzeSteps(job).map((step) => step.with?.category))
+    .flat()
+    .filter((category) => category !== undefined)
+    .map((category) => category!);
+
+  if (categories.length === 0) {
+    return undefined;
+  }
+  if (!categories.every((category) => category === categories[0])) {
+    throw new Error(
+      "Could not get category input since multiple categories were specified by the analysis step."
+    );
+  }
+  if (categories[0].includes("${{")) {
+    throw new Error(
+      "Could not get category input since it contained a dynamic value."
+    );
+  }
+  return categories[0];
+}