testutil: Enriched Equals with diff on error. (#7053)
## Example:
```
exp: []chunks.Meta{chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e160), MinTime:1, MaxTime:2}, chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e180), MinTime:3, MaxTime:3}, chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e1a0), MinTime:5, MaxTime:5}, chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e1c0), MinTime:24, MaxTime:6}}
got: []chunks.Meta{chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e280), MinTime:1, MaxTime:2}, chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e2a0), MinTime:3, MaxTime:3}, chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e220), MinTime:5, MaxTime:5}, chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e240), MinTime:6, MaxTime:6}}
```
Now:
```
exp: []chunks.Meta{chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e740), MinTime:1, MaxTime:2}, chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e760), MinTime:3, MaxTime:3}, chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e780), MinTime:5, MaxTime:5}, chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e7a0), MinTime:24, MaxTime:6}}
got: []chunks.Meta{chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e800), MinTime:1, MaxTime:2}, chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e820), MinTime:3, MaxTime:3}, chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e860), MinTime:5, MaxTime:5}, chunks.Meta{Ref:0x0, Chunk:(*chunkenc.XORChunk)(0xc00000e880), MinTime:6, MaxTime:6}}
Diff:
--- Expected
+++ Actual
@@ -50,3 +50,3 @@
}),
- MinTime: (int64) 24,
+ MinTime: (int64) 6,
MaxTime: (int64) 6
```
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
104a1313d4