Initial Commit

packages/media/audio/audio-codec-ffmpeg-wasm/tests/purity.test.ts

@@ -0,0 +1,109 @@
+import { existsSync, readdirSync, readFileSync, statSync } from "node:fs";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+import { describe, expect, it } from "@suaveplan/testing/runner";
+
+const here = dirname(fileURLToPath(import.meta.url));
+const srcRoot = join(here, "..", "src");
+const distRoot = join(here, "..", "dist");
+
+function walk(dir: string, out: string[] = []): string[] {
+    if (!existsSync(dir)) return out;
+    for (const entry of readdirSync(dir)) {
+        const p = join(dir, entry);
+        if (statSync(p).isDirectory()) walk(p, out);
+        else if (p.endsWith(".ts") || p.endsWith(".js")) out.push(p);
+    }
+    return out;
+}
+
+const FORBIDDEN_NODE_PATTERNS = [
+    /from\s+["']node:/,
+    /from\s+["']fs["']/,
+    /from\s+["']path["']/,
+    /from\s+["']crypto["']/,
+];
+
+describe("purity", () => {
+    it("source files do not import Node-only APIs at the top level", {
+        timeout: 5000,
+    }, () => {
+        const files = walk(srcRoot).filter(
+            (f) => !f.endsWith(".test.ts") && !f.endsWith(".d.ts")
+        );
+        const offenders: string[] = [];
+        for (const f of files) {
+            const text = readFileSync(f, "utf8");
+            for (const rx of FORBIDDEN_NODE_PATTERNS) {
+                if (rx.test(text)) offenders.push(`${f}: ${rx.source}`);
+            }
+        }
+        expect(offenders).toEqual([]);
+    });
+
+    it("@ffmpeg/core-mt is referenced only inside dynamic imports or comments", {
+        timeout: 5000,
+    }, () => {
+        const files = walk(srcRoot).filter(
+            (f) => !f.endsWith(".test.ts") && !f.endsWith(".d.ts")
+        );
+        for (const f of files) {
+            const text = readFileSync(f, "utf8");
+            const lines = text.split("\n");
+            for (const line of lines) {
+                if (!line.includes("@ffmpeg/core-mt")) continue;
+                const trimmed = line.trim();
+                if (trimmed.startsWith("//")) continue;
+                if (trimmed.startsWith("*")) continue;
+                if (line.includes("import(")) continue;
+                throw new Error(`disallowed reference in ${f}: ${line}`);
+            }
+        }
+    });
+
+    it("@ffmpeg/core is never reached via static import", {
+        timeout: 5000,
+    }, () => {
+        const files = walk(srcRoot).filter(
+            (f) => !f.endsWith(".test.ts") && !f.endsWith(".d.ts")
+        );
+        // Forbidden: `import … from "@ffmpeg/core"` / `import "@ffmpeg/core"`.
+        const STATIC_IMPORT =
+            /^\s*import\b[^;]*from\s+["']@ffmpeg\/core(?:-mt)?["']/;
+        for (const f of files) {
+            if (f.includes("ffmpeg-shim.d.ts")) continue;
+            const lines = readFileSync(f, "utf8").split("\n");
+            for (const line of lines) {
+                if (STATIC_IMPORT.test(line)) {
+                    throw new Error(`static import in ${f}: ${line}`);
+                }
+            }
+        }
+    });
+
+    it("importing the root module mutates no global state", {
+        timeout: 5000,
+    }, async () => {
+        // The act of importing the module is the verification — no exception
+        // means no top-level throw, and no spec covers any mutation outside
+        // the module's own ESM closure.
+        const mod = await import("../src/index.js");
+        expect(mod.FfmpegWasmCodec).toBeDefined();
+    });
+
+    it("dist/ — when built — contains no node: references", {
+        timeout: 5000,
+    }, () => {
+        if (!existsSync(distRoot)) {
+            // pre-build environment — skip
+            return;
+        }
+        const files = walk(distRoot);
+        for (const f of files) {
+            const text = readFileSync(f, "utf8");
+            for (const rx of FORBIDDEN_NODE_PATTERNS) {
+                expect(rx.test(text)).toBe(false);
+            }
+        }
+    });
+});