model.test.ts

import assert from 'node:assert/strict';
import { execFileSync, spawnSync } from 'node:child_process';
import { existsSync, mkdtempSync, readFileSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join } from 'node:path';
import { test } from 'node:test';
import { ARCHITECTURE_OWNERSHIP } from '../layering/architecture-ownership.ts';
import { resolveImportEdges } from '../layering/model.ts';
import {
  AUTHORITY_LABELS,
  authorityLabelsForEdge,
  buildGraph,
  collapseEdges,
  collectCycles,
  markTransitivelyReachableEdges,
  typeInversionsByPair,
} from './model.ts';

function sources(entries: Record<string, string>): Map<string, string> {
  return new Map(Object.entries(entries));
}

function authorityWorkspaceTargets(): Map<string, string> {
  return new Map([
    ['@agent-device/contracts/client', 'packages/contracts/src/facades/client.ts'],
    ['@agent-device/contracts/capture', 'packages/contracts/src/facades/capture.ts'],
    ['@agent-device/contracts/replay', 'packages/contracts/src/facades/replay.ts'],
    ['@agent-device/contracts/progress', 'packages/contracts/src/facades/progress.ts'],
  ]);
}

function authorityFixture(): Map<string, string> {
  return sources({
    'src/core/vocabulary-consumer.ts': [
      "import type { ClientShape } from '@agent-device/contracts/client';",
      "import type { CaptureShape } from '@agent-device/contracts/capture';",
      "import type { ReplayShape } from '@agent-device/contracts/replay';",
      "import type { ProgressShape } from '@agent-device/contracts/progress';",
    ].join('\n'),
    'src/daemon/capability-consumer.ts': [
      "import { createRequestRuntimeBindings } from './request-runtime-binding.ts';",
      "import { isSessionRecording } from './session-script-publication-capability.ts';",
    ].join('\n'),
    'src/daemon/state-consumer.ts': [
      "import type { SessionState } from './session-state.ts';",
      "import { SessionStore } from './session-store.ts';",
    ].join('\n'),
    'src/daemon/type-consumer.ts': "import type { SessionStore } from './session-store.ts';\n",
    'src/snapshot/policy-consumer.ts': [
      "import type { SessionState } from '../daemon/session-state.ts';",
      "import type { SessionRef } from '../daemon/session-state.ts';",
      "import './ordinary-target.ts';",
    ].join('\n'),
    'src/daemon/ordinary-consumer.ts': [
      "import { SessionState } from './session-state-store.ts';",
      "import { createRequestRuntimeBindingsExtra } from './request-runtime-binding.ts';",
    ].join('\n'),
    'src/daemon/session-state.ts':
      'export type SessionState = { name: string };\nexport type SessionRef = unknown;\n',
    'src/daemon/session-store.ts': 'export class SessionStore {}\n',
    'src/daemon/request-runtime-binding.ts': 'export function createRequestRuntimeBindings() {}\n',
    'src/daemon/session-script-publication-capability.ts':
      'export function isSessionRecording() {}\n',
    'src/daemon/session-state-store.ts': 'export const SessionState = 1;\n',
    'src/snapshot/ordinary-target.ts': 'export const ordinary = 1;\n',
    'packages/contracts/src/facades/client.ts': 'export type ClientShape = string;\n',
    'packages/contracts/src/facades/capture.ts': 'export type CaptureShape = string;\n',
    'packages/contracts/src/facades/replay.ts': 'export type ReplayShape = string;\n',
    'packages/contracts/src/facades/progress.ts': 'export type ProgressShape = string;\n',
  });
}

function graphEdge(
  graph: ReturnType<typeof buildGraph>,
  from: string,
  to: string,
): { kind: string; labels: readonly string[] } {
  const index = graph.edges.findIndex((edge) => edge.from === from && edge.to === to);
  assert.notEqual(index, -1, `${from} -> ${to} was not found`);
  return { kind: graph.edges[index]!.kind, labels: graph.edgeAuthorities[index]! };
}

test('authority overlay uses declared roots and symbols, keeps kind separate, and collapses labels', () => {
  const files = authorityFixture();
  const graph = buildGraph(files, resolveImportEdges(files, authorityWorkspaceTargets()));

  assert.deepEqual(
    graphEdge(graph, 'src/core/vocabulary-consumer.ts', 'packages/contracts/src/facades/client.ts'),
    { kind: 'type', labels: ['vocabulary'] },
  );
  assert.deepEqual(
    graphEdge(graph, 'src/daemon/capability-consumer.ts', 'src/daemon/request-runtime-binding.ts'),
    { kind: 'value', labels: ['capability'] },
  );
  assert.deepEqual(
    graphEdge(graph, 'src/daemon/state-consumer.ts', 'src/daemon/session-state.ts'),
    {
      kind: 'type',
      labels: ['live-state-shape'],
    },
  );
  assert.deepEqual(
    graphEdge(graph, 'src/daemon/state-consumer.ts', 'src/daemon/session-store.ts'),
    { kind: 'value', labels: ['live-state-authority'] },
  );
  assert.deepEqual(graphEdge(graph, 'src/daemon/type-consumer.ts', 'src/daemon/session-store.ts'), {
    kind: 'type',
    labels: ['live-state-authority'],
  });
  assert.deepEqual(
    graphEdge(graph, 'src/snapshot/policy-consumer.ts', 'src/snapshot/ordinary-target.ts'),
    { kind: 'value', labels: ['executable-policy'] },
  );
  assert.deepEqual(
    graphEdge(graph, 'src/daemon/ordinary-consumer.ts', 'src/daemon/session-state-store.ts'),
    { kind: 'value', labels: ['ordinary'] },
  );
  assert.deepEqual(
    graphEdge(graph, 'src/daemon/ordinary-consumer.ts', 'src/daemon/request-runtime-binding.ts'),
    { kind: 'value', labels: ['ordinary'] },
  );

  const stateEdges = resolveImportEdges(files, authorityWorkspaceTargets()).filter(
    (edge) =>
      edge.file === 'src/snapshot/policy-consumer.ts' &&
      edge.target === 'src/daemon/session-state.ts',
  );
  assert.equal(stateEdges.length, 2, 'the fixture must exercise raw same-pair imports');
  assert.deepEqual(
    graphEdge(graph, 'src/snapshot/policy-consumer.ts', 'src/daemon/session-state.ts'),
    {
      kind: 'type',
      labels: ['live-state-shape', 'executable-policy'],
    },
  );
  assert.deepEqual(graph.edgeAuthorities.length, graph.edges.length);
  assert.deepEqual(Object.keys(graph.authorityCounts), AUTHORITY_LABELS);
  assert.deepEqual(graph.authorityCounts, {
    vocabulary: 4,
    capability: 2,
    'live-state-shape': 2,
    'live-state-authority': 2,
    'executable-policy': 2,
    ordinary: 2,
  });
  assert.equal(authorityLabelsForEdge(stateEdges[0]!).includes('live-state-shape'), true);
});

test('live-state labels follow shared declarations and reject lookalike targets', () => {
  for (const declaration of ARCHITECTURE_OWNERSHIP.liveState) {
    assert.deepEqual(
      authorityLabelsForEdge({
        file: 'src/core/live-state-consumer.ts',
        target: declaration.root,
        spec: `./${declaration.root.split('/').at(-1)}`,
        dynamic: false,
        typeOnly: true,
        line: 1,
        symbols: [...declaration.exports],
        fromZone: 'core',
        toZone: 'daemon-server',
      }),
      [declaration.kind],
    );
  }

  const sessionState = ARCHITECTURE_OWNERSHIP.liveState.find(
    ({ kind }) => kind === 'live-state-shape',
  )!;
  assert.deepEqual(
    authorityLabelsForEdge({
      file: 'src/core/live-state-consumer.ts',
      target: 'src/daemon/session-state-store.ts',
      spec: './session-state-store.ts',
      dynamic: false,
      typeOnly: true,
      line: 1,
      symbols: [...sessionState.exports],
      fromZone: 'core',
      toZone: 'daemon-server',
    }),
    ['ordinary'],
  );
});

test('collapseEdges keeps one edge per pair at the strongest kind', () => {
  const edges = resolveImportEdges(
    sources({
      'src/core/a.ts': [
        "import type { Shape } from './b.ts';",
        "import { run } from './b.ts';",
        "import type { Other } from './c.ts';",
        "void import('./d.ts');",
      ].join('\n'),
      'src/core/b.ts': 'export const run = 1;',
      'src/core/c.ts': 'export type Other = string;',
      'src/core/d.ts': 'export const lazy = 1;',
    }),
  );

  assert.deepEqual(
    collapseEdges(edges).map((edge) => ({ to: edge.to, kind: edge.kind })),
    [
      { to: 'src/core/b.ts', kind: 'value' },
      { to: 'src/core/c.ts', kind: 'type' },
      { to: 'src/core/d.ts', kind: 'dynamic' },
    ],
  );
});

test('flags only value edges whose target is already reachable at distance >= 2', () => {
  const edges = collapseEdges(
    resolveImportEdges(
      sources({
        // a -> b -> c means c is reachable from a at distance 2, so the direct a -> c edge is
        // FLAGGED. Note it is not removable: `b` re-exports c's binding under a different name,
        // so deleting a -> c would break a's `c` import. That gap is the point of the rename —
        // this measures module reachability, not safe removal. a -> d is the only route to d.
        'src/core/a.ts': [
          "import { b } from './b.ts';",
          "import { c } from './c.ts';",
          "import { d } from './d.ts';",
        ].join('\n'),
        'src/core/b.ts': "export { c as b } from './c.ts';",
        'src/core/c.ts': 'export const c = 1;',
        'src/core/d.ts': 'export const d = 1;',
      }),
    ),
  );
  markTransitivelyReachableEdges(edges);

  const flagged = edges
    .filter((edge) => edge.transitivelyReachable)
    .map((edge) => `${edge.from} -> ${edge.to}`);
  assert.deepEqual(flagged, ['src/core/a.ts -> src/core/c.ts']);
});

test('a type-only shortcut is never flagged against a value path', () => {
  const edges = collapseEdges(
    resolveImportEdges(
      sources({
        'src/core/a.ts': ["import { b } from './b.ts';", "import type { C } from './c.ts';"].join(
          '\n',
        ),
        'src/core/b.ts': "export { c as b } from './c.ts';",
        'src/core/c.ts': 'export type C = string;\nexport const c = 1;',
      }),
    ),
  );
  markTransitivelyReachableEdges(edges);

  assert.deepEqual(
    edges.filter((edge) => edge.transitivelyReachable),
    [],
  );
});

test('collectCycles separates gate-rejected value cycles from type-only and dynamic loops', () => {
  const valueCycle = collectCycles(
    resolveImportEdges(
      sources({
        'src/core/a.ts': "import { b } from './b.ts';\nexport const a = 1;",
        'src/core/b.ts': "import { a } from './a.ts';\nexport const b = 1;",
      }),
    ),
  );
  assert.deepEqual(
    valueCycle.map((cycle) => cycle.kind),
    ['value'],
  );

  const typeCycle = collectCycles(
    resolveImportEdges(
      sources({
        'src/core/a.ts': "import type { B } from './b.ts';\nexport type A = B;",
        'src/core/b.ts': "import type { A } from './a.ts';\nexport type B = A | null;",
      }),
    ),
  );
  assert.deepEqual(
    typeCycle.map((cycle) => cycle.kind),
    ['type'],
  );

  const dynamicCycle = collectCycles(
    resolveImportEdges(
      sources({
        'src/core/a.ts': "export const a = () => import('./b.ts');",
        'src/core/b.ts': "export const b = () => import('./a.ts');",
      }),
    ),
  );
  assert.deepEqual(
    dynamicCycle.map((cycle) => cycle.kind),
    ['dynamic'],
  );
});

test('buildGraph reports zone membership, degrees, and cross-zone edge counts', () => {
  const files = sources({
    'packages/kernel/src/errors.ts': 'export const fail = 1;\n',
    'src/core/interactors/tap.ts': "import { fail } from '@agent-device/kernel/errors';\n",
    'src/commands/tap.ts': [
      "import { fail } from '@agent-device/kernel/errors';",
      "import '../core/interactors/tap.ts';",
    ].join('\n'),
  });
  const graph = buildGraph(files, resolveImportEdges(files));

  const kernel = graph.nodes.find((node) => node.id === 'packages/kernel/src/errors.ts')!;
  assert.equal(kernel.zone, 'kernel');
  assert.equal(kernel.fanIn, 2);
  assert.equal(kernel.fanOut, 0);

  // A non-root zone member resolves to its folder, not to `(root)`.
  const interactor = graph.nodes.find((node) => node.id === 'src/core/interactors/tap.ts')!;
  assert.equal(interactor.zone, 'core');

  assert.deepEqual(
    graph.zoneEdges.map((edge) => `${edge.from} -> ${edge.to} (${edge.count})`),
    ['commands -> core (1)', 'commands -> kernel (1)', 'core -> kernel (1)'],
  );
  assert.deepEqual(
    graph.zones.map((zone) => `${zone.id}:${zone.classification}`),
    ['kernel:unranked', 'core:ranked', 'commands:ranked'],
  );
});

// `typeInversions` is the report's view of R6 over the RAW edges: a module imported both lazily
// and for its types keeps its type-only edge, where `collapseEdges` ranks `dynamic` above `type`
// and would lose it.
test('typeInversionsByPair counts raw type-only edges once per file pair', () => {
  const files = sources({
    'src/commands/tap.ts': 'export type TapOptions = { retries: number };\n',
    'src/core/interactors/tap.ts': [
      "import type { TapOptions } from '../../commands/tap.ts';",
      "import type { TapOptions as Again } from '../../commands/tap.ts';",
      'export type Both = TapOptions | Again;',
    ].join('\n'),
    'src/core/interactors/lazy.ts': [
      "import type { TapOptions } from '../../commands/tap.ts';",
      "export const load = (): Promise<unknown> => import('../../commands/tap.ts');",
      'export type Options = TapOptions;',
    ].join('\n'),
    'src/core/interactors/value.ts': "import '../../commands/tap.ts';\n",
  });
  const edges = resolveImportEdges(files);

  assert.deepEqual(typeInversionsByPair(edges), { 'core -> commands': 2 });
  assert.deepEqual(buildGraph(files, edges).typeInversions, { 'core -> commands': 2 });
});

// A raw NUL byte in a source file makes Git classify it as binary, which hides the whole diff
// behind `- -` and leaves the file unreviewable. This module used a literal NUL as a map-key
// delimiter and shipped that way through a review; it is now the escape sequence, identical at
// runtime and textual on disk. Guarded repo-wide rather than for this one file, because nothing
// else would catch a recurrence and the failure mode is silent: the code works, the review does not.
test('no tracked TypeScript source contains a raw NUL byte', () => {
  const tracked = execFileSync('git', ['ls-files', 'src/*.ts', 'src/**/*.ts', 'scripts/**/*.ts'], {
    encoding: 'utf8',
  })
    .split('\n')
    .filter(Boolean);

  const binary = tracked.filter((file) => readFileSync(file).includes(0));
  assert.deepEqual(
    binary,
    [],
    'these files contain a raw NUL byte, so Git treats them as binary and hides their diff. ' +
      'Use a unicode escape instead of a literal control character.',
  );
});

// build.ts had no coverage at all: every test above exercises model.ts, so the CLI could break its
// output path, JSON shape or summary without anything failing. These run it as a subprocess, which
// is the only way to cover argument handling and the file it actually writes.

function runBuild(args: readonly string[]): {
  status: number | null;
  stdout: string;
  stderr: string;
} {
  const result = spawnSync(
    process.execPath,
    ['--experimental-strip-types', 'scripts/depgraph/build.ts', ...args],
    { encoding: 'utf8' },
  );
  return { status: result.status, stdout: result.stdout ?? '', stderr: result.stderr ?? '' };
}

test('build.ts writes the default path and a summary consistent with the JSON', () => {
  const { status, stdout } = runBuild([]);
  assert.equal(status, 0, stdout);

  const payload = JSON.parse(readFileSync('.tmp/depgraph/graph.json', 'utf8')) as {
    generated: { commit: string; files: number; edges: number };
    zones: { id: string; rank: number | null }[];
    nodes: unknown[];
    edges: [number, number, number, number][];
    edgeAuthorities: string[][];
    authorityCounts: Record<string, number>;
    typeInversions: Record<string, number>;
  };

  // Wire shape: the fields a consumer queries. A rename here is a breaking change for any script
  // following README.md, so it is pinned rather than assumed.
  for (const field of [
    'generated',
    'zones',
    'zoneEdges',
    'nodes',
    'edges',
    'cycles',
    'typeInversions',
  ]) {
    assert.ok(field in payload, `legacy payload field ${field} disappeared`);
  }
  assert.equal(payload.nodes.length, payload.generated.files);
  assert.equal(payload.edges.length, payload.generated.edges);
  assert.equal(payload.edgeAuthorities.length, payload.edges.length);
  assert.equal(
    payload.edges.every((edge) => edge.length === 4),
    true,
  );
  assert.deepEqual(Object.keys(payload.authorityCounts), AUTHORITY_LABELS);
  assert.ok(payload.zones.length > 0);
  assert.ok(Object.keys(payload.typeInversions).length > 0);

  // The printed summary must agree with the payload it was derived from.
  const inversions = Object.values(payload.typeInversions).reduce((sum, n) => sum + n, 0);
  assert.match(
    stdout,
    new RegExp(`${payload.generated.files} files, ${payload.generated.edges} edges`),
  );
  assert.match(stdout, new RegExp(`type-only spine inversions \\(R6\\): ${inversions}`));
  const reachable = payload.edges.filter(([, , , flags]) => (flags & 2) !== 0).length;
  assert.match(stdout, new RegExp(`reachable at distance >= 2: ${reachable}`));
});

test('build.ts honours --out and reports the path it wrote', () => {
  const out = join(mkdtempSync(join(tmpdir(), 'depgraph-')), 'custom.json');
  const { status, stdout } = runBuild(['--out', out]);
  assert.equal(status, 0, stdout);
  assert.ok(existsSync(out), `expected ${out} to exist`);
  JSON.parse(readFileSync(out, 'utf8'));
  assert.ok(stdout.includes('custom.json'), stdout);
});

test('build.ts falls back to the default path when --out has no value', () => {
  // Not an error path today: a trailing `--out` is ignored rather than rejected. Pinned so the
  // behaviour is a decision rather than an accident, and so changing it is a visible diff.
  const { status, stdout } = runBuild(['--out']);
  assert.equal(status, 0, stdout);
  assert.ok(stdout.includes('.tmp/depgraph/graph.json'), stdout);
});