feat: add inspect npm pack function (#174)

This allows snapshot testing of package content prior to publishing.

Author: Thomaash

__snapshots__/test/package.test.ts.js

@@ -0,0 +1,43 @@
+exports['package exported files 1'] = {
+  "name": "vis-dev-utils                           ",
+  "files": [
+    "        LICENSE-APACHE-2.0",
+    "        LICENSE-MIT",
+    "        README.md",
+    "        babel-preset/index.js",
+    "        babel-register/index.js",
+    "        babel-register/index.js.map",
+    "        bin/generate-examples-index.js",
+    "        bin/generate-examples-index.js.map",
+    "        declarations/constants.d.ts",
+    "        declarations/constants.d.ts.map",
+    "        declarations/generate-rollup-configuration/index.d.ts",
+    "        declarations/generate-rollup-configuration/index.d.ts.map",
+    "        declarations/header.d.ts",
+    "        declarations/header.d.ts.map",
+    "        declarations/index.d.ts",
+    "        declarations/index.d.ts.map",
+    "        declarations/inspect-npm-pack.d.ts",
+    "        declarations/inspect-npm-pack.d.ts.map",
+    "        declarations/util.d.ts",
+    "        declarations/util.d.ts.map",
+    "        dist/assets/bundle-file.d.ts",
+    "        dist/assets/bundle-index.d.ts",
+    "        dist/assets/bundle-index.js",
+    "        dist/assets/bundle-root.d.ts",
+    "        dist/assets/bundle-root.js",
+    "        dist/vis-dev-utils.cjs.js",
+    "        dist/vis-dev-utils.cjs.js.map",
+    "        dist/vis-dev-utils.esm.js",
+    "        dist/vis-dev-utils.esm.js.map",
+    "        lib/header.d.ts",
+    "        lib/header.d.ts.map",
+    "        lib/header.js",
+    "        lib/header.js.map",
+    "        lib/inspect-npm-pack.d.ts",
+    "        lib/inspect-npm-pack.d.ts.map",
+    "        lib/inspect-npm-pack.js",
+    "        lib/inspect-npm-pack.js.map",
+    "        package.json"
+  ]
+}

src/module/index.ts

@@ -1,3 +1,4 @@
 export * from "./constants";
 export * from "./generate-rollup-configuration";
 export * from "./header";
+export * from "./inspect-npm-pack";

src/module/inspect-npm-pack.ts

@@ -0,0 +1,57 @@
+import { spawnSync } from "child_process";
+
+function runNpmPack(): string[] {
+  const result = spawnSync("npm", ["pack", "--dry-run-a"], {
+    env: { ...process.env, LC_ALL: "C" },
+    stdio: "pipe",
+    encoding: "utf-8"
+  });
+
+  return result.stderr.split(/[\r\n]+/);
+}
+
+function extractFiles(lines: string[]): string[] {
+  const fileListingStart = lines.indexOf(
+    "npm notice === Tarball Contents === "
+  );
+  const fileListingEnd = lines.indexOf("npm notice === Tarball Details === ");
+
+  const files = lines
+    .slice(fileListingStart + 1, fileListingEnd)
+    .map((line): string => line.replace(/^npm notice /, ""))
+    .map((line): string => line.trim())
+    .map((line): string =>
+      line.replace(
+        /^([^ ]+) +(.*)/,
+        (_, size, path): string =>
+          `${path}${size === "0" ? "(empty)" : "       "}`
+      )
+    )
+    .sort()
+    .map(line => line.replace(/^(.*)(.{7})$/, "$2 $1"));
+
+  return files;
+}
+
+function extractName(lines: string[]): string {
+  const nameLine = lines.find((line): boolean =>
+    /^npm notice name:/.test(line)
+  );
+
+  if (nameLine == null) {
+    throw new Error("Can't find the name of the package.");
+  }
+
+  return nameLine.replace(/^npm notice name: */, "");
+}
+
+export function inspectNpmPack(): { name: string; files: string[] } {
+  const lines = runNpmPack();
+  const files = extractFiles(lines);
+  const name = extractName(lines);
+
+  return {
+    name,
+    files
+  };
+}

test/package.test.ts

@@ -0,0 +1,9 @@
+import snapshot from "snap-shot-it";
+
+import { inspectNpmPack } from "../lib/inspect-npm-pack";
+
+describe("package", function(): void {
+  it("exported files", function(): void {
+    snapshot(inspectNpmPack());
+  });
+});

tsconfig.internal.json

@@ -9,5 +9,9 @@
     "target": "es2015"
   },
   "exclude": ["node_modules", "**/__tests__/*"],
-  "include": ["@types ", "src/module/header.ts"]
+  "include": [
+    "@types",
+    "src/module/header.ts",
+    "src/module/inspect-npm-pack.ts"
+  ]
 }