refactor: eliminate jscpd clones and boost tests

src/infra/npm-pack-install.ts

@@ -0,0 +1,73 @@
+import {
+  type NpmIntegrityDrift,
+  type NpmSpecResolution,
+  packNpmSpecToArchive,
+  withTempDir,
+} from "./install-source-utils.js";
+import {
+  type NpmIntegrityDriftPayload,
+  resolveNpmIntegrityDriftWithDefaultMessage,
+} from "./npm-integrity.js";
+
+export type NpmSpecArchiveInstallFlowResult<TResult extends { ok: boolean }> =
+  | {
+      ok: false;
+      error: string;
+    }
+  | {
+      ok: true;
+      installResult: TResult;
+      npmResolution: NpmSpecResolution;
+      integrityDrift?: NpmIntegrityDrift;
+    };
+
+export async function installFromNpmSpecArchive<TResult extends { ok: boolean }>(params: {
+  tempDirPrefix: string;
+  spec: string;
+  timeoutMs: number;
+  expectedIntegrity?: string;
+  onIntegrityDrift?: (payload: NpmIntegrityDriftPayload) => boolean | Promise<boolean>;
+  warn?: (message: string) => void;
+  installFromArchive: (params: { archivePath: string }) => Promise<TResult>;
+}): Promise<NpmSpecArchiveInstallFlowResult<TResult>> {
+  return await withTempDir(params.tempDirPrefix, async (tmpDir) => {
+    const packedResult = await packNpmSpecToArchive({
+      spec: params.spec,
+      timeoutMs: params.timeoutMs,
+      cwd: tmpDir,
+    });
+    if (!packedResult.ok) {
+      return packedResult;
+    }
+
+    const npmResolution: NpmSpecResolution = {
+      ...packedResult.metadata,
+      resolvedAt: new Date().toISOString(),
+    };
+
+    const driftResult = await resolveNpmIntegrityDriftWithDefaultMessage({
+      spec: params.spec,
+      expectedIntegrity: params.expectedIntegrity,
+      resolution: npmResolution,
+      onIntegrityDrift: params.onIntegrityDrift,
+      warn: params.warn,
+    });
+    if (driftResult.error) {
+      return {
+        ok: false,
+        error: driftResult.error,
+      };
+    }
+
+    const installResult = await params.installFromArchive({
+      archivePath: packedResult.archivePath,
+    });
+
+    return {
+      ok: true,
+      installResult,
+      npmResolution,
+      integrityDrift: driftResult.integrityDrift,
+    };
+  });
+}