|
| 1 | +import torch |
| 2 | +import sys |
| 3 | +sys.path.append('..') |
| 4 | + |
| 5 | +from model_components.backbone import Backbone |
| 6 | + |
| 7 | + |
| 8 | +class _StubBackboneWithFeatureInfo(torch.nn.Module): |
| 9 | + """Channels-first backbone exposing timm-style feature_info.""" |
| 10 | + |
| 11 | + def __init__(self): |
| 12 | + super().__init__() |
| 13 | + self.stage0 = torch.nn.Conv2d(3, 32, 3, stride=2, padding=1) |
| 14 | + self.stage1 = torch.nn.Conv2d(32, 48, 3, stride=2, padding=1) |
| 15 | + self.stage2 = torch.nn.Conv2d(48, 64, 3, stride=2, padding=1) |
| 16 | + self.feature_info = [{"num_chs": 32}, {"num_chs": 48}, {"num_chs": 64}] |
| 17 | + |
| 18 | + def forward(self, x): |
| 19 | + s0 = self.stage0(x) |
| 20 | + s1 = self.stage1(s0) |
| 21 | + s2 = self.stage2(s1) |
| 22 | + return [s0, s1, s2] |
| 23 | + |
| 24 | + |
| 25 | +class _StubBackboneNoFeatureInfo(torch.nn.Module): |
| 26 | + """Channels-first backbone with NO feature_info (probe fallback path).""" |
| 27 | + |
| 28 | + def __init__(self): |
| 29 | + super().__init__() |
| 30 | + self.stage0 = torch.nn.Conv2d(3, 24, 3, stride=2, padding=1) |
| 31 | + self.stage1 = torch.nn.Conv2d(24, 56, 3, stride=2, padding=1) |
| 32 | + self.stage2 = torch.nn.Conv2d(56, 112, 3, stride=2, padding=1) |
| 33 | + |
| 34 | + def forward(self, x): |
| 35 | + s0 = self.stage0(x) |
| 36 | + s1 = self.stage1(s0) |
| 37 | + s2 = self.stage2(s1) |
| 38 | + return [s0, s1, s2] |
| 39 | + |
| 40 | + |
| 41 | +class _StubBackboneSwinLike(torch.nn.Module): |
| 42 | + """Channels-last backbone (B, H, W, C) — exercises permute branch.""" |
| 43 | + |
| 44 | + def __init__(self): |
| 45 | + super().__init__() |
| 46 | + self.stage0 = torch.nn.Conv2d(3, 32, 3, stride=2, padding=1) |
| 47 | + self.stage1 = torch.nn.Conv2d(32, 48, 3, stride=2, padding=1) |
| 48 | + self.feature_info = [{"num_chs": 32}, {"num_chs": 48}] |
| 49 | + |
| 50 | + def forward(self, x): |
| 51 | + s0_cf = self.stage0(x) # [B, 32, H, W] |
| 52 | + s1_cf = self.stage1(s0_cf) # [B, 48, H, W] |
| 53 | + s0 = s0_cf.permute(0, 2, 3, 1).contiguous() # [B, H, W, 32] |
| 54 | + s1 = s1_cf.permute(0, 2, 3, 1).contiguous() # [B, H, W, 48] |
| 55 | + return [s0, s1] |
| 56 | + |
| 57 | + |
| 58 | +class TestBackboneChannelDiscovery: |
| 59 | + """Cover the backbone_channels discovery + layout-detection in Backbone.""" |
| 60 | + |
| 61 | + def _make_backbone(self, monkeypatch, stub_module): |
| 62 | + # Patch the registry call so build_backbone returns our stub. |
| 63 | + monkeypatch.setattr( |
| 64 | + "model_components.backbone.build_backbone", |
| 65 | + lambda *a, **kw: stub_module, |
| 66 | + ) |
| 67 | + return Backbone(backbone="stub", is_pretrained=False) |
| 68 | + |
| 69 | + def test_feature_info_path_sums_channels(self, monkeypatch): |
| 70 | + bb = self._make_backbone(monkeypatch, _StubBackboneWithFeatureInfo()) |
| 71 | + assert bb.backbone_channels == 32 + 48 + 64 |
| 72 | + |
| 73 | + def test_probe_fallback_when_feature_info_missing(self, monkeypatch): |
| 74 | + bb = self._make_backbone(monkeypatch, _StubBackboneNoFeatureInfo()) |
| 75 | + # No feature_info — channels recovered via probing. |
| 76 | + assert bb.backbone_channels == 24 + 56 + 112 |
| 77 | + |
| 78 | + def test_feature_info_channels_match_forward_output(self, monkeypatch, device): |
| 79 | + """sum(feature_info channels) must equal the actual concat-channel dim |
| 80 | + of the forward output.""" |
| 81 | + bb = self._make_backbone(monkeypatch, _StubBackboneWithFeatureInfo()).to(device) |
| 82 | + x = torch.randn(2, 3, 32, 32, device=device) |
| 83 | + feats = bb(x) |
| 84 | + total_c = sum(f.shape[1] for f in feats) |
| 85 | + assert total_c == bb.backbone_channels |
| 86 | + |
| 87 | + def test_probe_channels_match_forward_output(self, monkeypatch, device): |
| 88 | + bb = self._make_backbone(monkeypatch, _StubBackboneNoFeatureInfo()).to(device) |
| 89 | + x = torch.randn(2, 3, 32, 32, device=device) |
| 90 | + feats = bb(x) |
| 91 | + total_c = sum(f.shape[1] for f in feats) |
| 92 | + assert total_c == bb.backbone_channels |
| 93 | + |
| 94 | + def test_channels_last_backbone_is_permuted(self, monkeypatch, device): |
| 95 | + """Channels-last (B, H, W, C) output must be permuted to (B, C, H, W) |
| 96 | + based on tensor shape, NOT on the backbone name.""" |
| 97 | + bb = self._make_backbone(monkeypatch, _StubBackboneSwinLike()).to(device) |
| 98 | + x = torch.randn(2, 3, 32, 32, device=device) |
| 99 | + feats = bb(x) |
| 100 | + # After Backbone.forward, every feature must be channels-first with the |
| 101 | + # expected channel count at dim 1. |
| 102 | + assert feats[0].shape[1] == 32 |
| 103 | + assert feats[1].shape[1] == 48 |
| 104 | + |
| 105 | + def test_channels_first_backbone_not_permuted(self, monkeypatch, device): |
| 106 | + bb = self._make_backbone(monkeypatch, _StubBackboneWithFeatureInfo()).to(device) |
| 107 | + x = torch.randn(2, 3, 32, 32, device=device) |
| 108 | + feats = bb(x) |
| 109 | + for f, expected in zip(feats, [32, 48, 64]): |
| 110 | + assert f.shape[1] == expected |
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