chore: eliminate all 57 build warnings

[cloud-hai-vo]

Problem

Build produced 57 warnings across 3 categories, cluttering CI output and hiding real issues.

Fix

Warning	Count	Fix
CS8604 nullable arg	15	! where null already checked upstream
CS8602 nullable deref	18	! in test assertions
NU1701 package compat	12	<NoWarn> in Analyzers.Tests csproj
xUnit1031 blocking task	9	async Task + await Task.WhenAll
ExpressionBuilder null safety	3	Null check before nestedDel call (also a review fix)

Build now: 0 warnings across all TFMs.

Test plan

• 348 unit tests pass
• 0 warnings on dotnet build --configuration Release

🤖 Generated with Claude Code

[github-actions]

📊 Benchmark Results

Generated: 2026-03-27 00:11 UTC  ·  Download full artifacts

Column guide:
Mean = average execution time  ·  Error = half of 99.9 % confidence interval  ·  StdDev = standard deviation  ·  Min / Median / Max = statistical range  ·  Ratio = vs Manual baseline (lower = closer to hand-written speed)  ·  RatioSD = ratio std dev  ·  Rank = 1 is fastest  ·  Gen0/1/2 = GC collections per 1 000 ops  ·  Allocated = managed heap per operation  ·  Alloc Ratio = allocation ratio vs baseline

🔵 Flat Mapping — 10-property object

Method	Mean	Error	StdDev	Min	Median	Max	Ratio	RatioSD	Rank	Gen0	Allocated	Alloc Ratio
Manual	14.38 ns	2.998 ns	0.164 ns	14.24 ns	14.33 ns	14.56 ns	1.00	0.01	1	0.0048	80 B	1.00
EggMapper	25.03 ns	2.457 ns	0.135 ns	24.87 ns	25.09 ns	25.12 ns	1.74	0.02	2	0.0048	80 B	1.00
AutoMapper	80.10 ns	4.076 ns	0.223 ns	79.85 ns	80.17 ns	80.28 ns	5.57	0.06	3	0.0048	80 B	1.00
Mapster	27.63 ns	2.297 ns	0.126 ns	27.55 ns	27.56 ns	27.78 ns	1.92	0.02	2	0.0048	80 B	1.00
MapperlyMap	14.85 ns	0.870 ns	0.048 ns	14.81 ns	14.84 ns	14.90 ns	1.03	0.01	1	0.0048	80 B	1.00
AgileMapper	486.69 ns	22.273 ns	1.221 ns	485.84 ns	486.13 ns	488.09 ns	33.86	0.34	4	0.0200	344 B	4.30
EggMapperGenerator	15.08 ns	3.448 ns	0.189 ns	14.91 ns	15.06 ns	15.28 ns	1.05	0.02	1	0.0048	80 B	1.00
EggMapperClassMapper	15.35 ns	5.355 ns	0.294 ns	15.03 ns	15.44 ns	15.59 ns	1.07	0.02	1	0.0048	80 B	1.00

🟡 Flattening — 2 nested objects → 8 flat properties

Method	Mean	Error	StdDev	Min	Median	Max	Ratio	RatioSD	Rank	Gen0	Allocated	Alloc Ratio
Manual	18.53 ns	2.156 ns	0.118 ns	18.39 ns	18.60 ns	18.60 ns	1.00	0.01	1	0.0048	80 B	1.00
EggMap	29.23 ns	10.672 ns	0.585 ns	28.58 ns	29.38 ns	29.71 ns	1.58	0.03	3	0.0048	80 B	1.00
AutoMapper	92.68 ns	3.158 ns	0.173 ns	92.49 ns	92.71 ns	92.83 ns	5.00	0.03	4	0.0048	80 B	1.00
Mapster	35.28 ns	2.258 ns	0.124 ns	35.18 ns	35.25 ns	35.42 ns	1.90	0.01	3	0.0048	80 B	1.00
MapperlyMap	23.31 ns	21.513 ns	1.179 ns	22.63 ns	22.63 ns	24.67 ns	1.26	0.06	2	0.0062	104 B	1.30
AgileMapper	506.28 ns	1.663 ns	0.091 ns	506.22 ns	506.24 ns	506.39 ns	27.32	0.15	5	0.0200	344 B	4.30

🟣 Deep Mapping — 2 nested address objects

Method	Mean	Error	StdDev	Min	Median	Max	Ratio	RatioSD	Rank	Gen0	Allocated	Alloc Ratio
Manual	53.42 ns	15.473 ns	0.848 ns	52.49 ns	53.62 ns	54.16 ns	1.00	0.02	1	0.0162	272 B	1.00
EggMapper	63.30 ns	18.893 ns	1.036 ns	62.52 ns	62.89 ns	64.47 ns	1.19	0.02	1	0.0162	272 B	1.00
AutoMapper	117.36 ns	7.599 ns	0.417 ns	117.11 ns	117.12 ns	117.84 ns	2.20	0.03	2	0.0162	272 B	1.00
Mapster	66.42 ns	8.875 ns	0.486 ns	65.88 ns	66.54 ns	66.83 ns	1.24	0.02	1	0.0162	272 B	1.00
MapperlyMap	48.45 ns	5.750 ns	0.315 ns	48.12 ns	48.48 ns	48.75 ns	0.91	0.01	1	0.0162	272 B	1.00
AgileMapper	506.85 ns	31.783 ns	1.742 ns	505.15 ns	506.78 ns	508.63 ns	9.49	0.13	3	0.0248	424 B	1.56

🟢 Complex Mapping — nested object + collection

Method	Mean	Error	StdDev	Min	Median	Max	Ratio	RatioSD	Rank	Gen0	Allocated	Alloc Ratio
Manual	72.14 ns	14.93 ns	0.818 ns	71.36 ns	72.08 ns	72.99 ns	1.00	0.01	1	0.0191	320 B	1.00
EggMapper	100.19 ns	17.52 ns	0.961 ns	99.09 ns	100.58 ns	100.89 ns	1.39	0.02	2	0.0191	320 B	1.00
AutoMapper	157.23 ns	18.10 ns	0.992 ns	156.15 ns	157.45 ns	158.09 ns	2.18	0.02	3	0.0196	328 B	1.02
Mapster	92.02 ns	14.70 ns	0.806 ns	91.10 ns	92.39 ns	92.58 ns	1.28	0.02	2	0.0191	320 B	1.00
MapperlyMap	72.19 ns	13.92 ns	0.763 ns	71.33 ns	72.48 ns	72.77 ns	1.00	0.01	1	0.0191	320 B	1.00
AgileMapper	572.44 ns	50.47 ns	2.767 ns	569.52 ns	572.80 ns	575.02 ns	7.94	0.08	4	0.0315	528 B	1.65

🟠 Collection — 100-item List<T>

Method	Mean	Error	StdDev	Min	Median	Max	Ratio	RatioSD	Rank	Gen0	Gen1	Allocated	Alloc Ratio
Manual	1.732 μs	0.2412 μs	0.0132 μs	1.720 μs	1.729 μs	1.746 μs	1.00	0.01	1	0.5283	0.0172	8.65 KB	1.00
EggMapper	1.741 μs	0.2083 μs	0.0114 μs	1.729 μs	1.744 μs	1.752 μs	1.01	0.01	1	0.5283	0.0172	8.65 KB	1.00
AutoMapper	2.353 μs	0.5409 μs	0.0296 μs	2.319 μs	2.368 μs	2.372 μs	1.36	0.02	2	0.6065	0.0191	9.95 KB	1.15
Mapster	1.810 μs	0.7127 μs	0.0391 μs	1.774 μs	1.803 μs	1.852 μs	1.04	0.02	1	0.5283	0.0172	8.65 KB	1.00
MapperlyMap	1.854 μs	0.4237 μs	0.0232 μs	1.836 μs	1.845 μs	1.880 μs	1.07	0.01	1	0.5283	0.0172	8.65 KB	1.00
AgileMapper	2.615 μs	0.4369 μs	0.0239 μs	2.588 μs	2.624 μs	2.634 μs	1.51	0.02	2	0.5417	0.0153	8.91 KB	1.03

🟠 Collection — 100-item List<T>

Method	Mean	Error	StdDev	Min	Median	Max	Ratio	RatioSD	Rank	Gen0	Gen1	Allocated	Alloc Ratio
Manual	5.174 μs	0.3606 μs	0.0198 μs	5.161 μs	5.164 μs	5.196 μs	1.00	0.00	1	1.6708	0.0916	27.4 KB	1.00
EggMapper	5.646 μs	0.4772 μs	0.0262 μs	5.616 μs	5.656 μs	5.666 μs	1.09	0.01	1	1.6708	0.0916	27.4 KB	1.00
AutoMapper	6.372 μs	0.4758 μs	0.0261 μs	6.346 μs	6.373 μs	6.398 μs	1.23	0.01	1	1.7548	0.1068	28.7 KB	1.05
Mapster	5.694 μs	0.6734 μs	0.0369 μs	5.653 μs	5.704 μs	5.725 μs	1.10	0.01	1	1.6708	0.0916	27.4 KB	1.00
MapperlyMap	5.285 μs	1.6353 μs	0.0896 μs	5.208 μs	5.264 μs	5.383 μs	1.02	0.02	1	1.6785	0.0992	27.42 KB	1.00
AgileMapper	5.146 μs	0.3460 μs	0.0190 μs	5.134 μs	5.137 μs	5.168 μs	0.99	0.00	1	1.0223	0.0610	16.72 KB	0.61

🟠 Collection — 100-item List<T>

Method	Mean	Error	StdDev	Min	Median	Max	Ratio	RatioSD	Rank	Gen0	Gen1	Allocated	Alloc Ratio
Manual	16.50 μs	3.727 μs	0.204 μs	16.35 μs	16.41 μs	16.73 μs	1.00	0.02	1	5.2490	1.3123	85.99 KB	1.00
EggMapper	17.76 μs	1.684 μs	0.092 μs	17.65 μs	17.80 μs	17.82 μs	1.08	0.01	1	5.2490	1.3123	85.99 KB	1.00
AutoMapper	21.00 μs	0.666 μs	0.036 μs	20.97 μs	20.98 μs	21.04 μs	1.27	0.01	1	5.7678	1.4343	94.34 KB	1.10
Mapster	17.05 μs	3.607 μs	0.198 μs	16.84 μs	17.09 μs	17.23 μs	1.03	0.02	1	5.2490	1.3123	85.99 KB	1.00
MapperlyMap	18.17 μs	0.527 μs	0.029 μs	18.15 μs	18.17 μs	18.20 μs	1.10	0.01	1	5.2490	1.2817	86.02 KB	1.00
AgileMapper	20.27 μs	2.938 μs	0.161 μs	20.13 μs	20.24 μs	20.45 μs	1.23	0.02	1	5.2795	1.3123	86.25 KB	1.00

⚪ Startup / Configuration time

Method	Mean	Error	StdDev	Min	Median	Max	Ratio	RatioSD	Rank	Gen0	Gen1	Allocated	Alloc Ratio
EggMapperStartup	1,306.824 μs	1,389.9702 μs	76.1890 μs	1,230.727 μs	1,306.641 μs	1,383.104 μs	1.002	0.07	3	3.9063	1.9531	94.82 KB	1.00
AutoMapperStartup	452.114 μs	888.0934 μs	48.6794 μs	408.306 μs	443.518 μs	504.519 μs	0.347	0.04	2	5.8594	-	104.07 KB	1.10
MapsterStartup	2.477 μs	0.5669 μs	0.0311 μs	2.447 μs	2.475 μs	2.509 μs	0.002	0.00	1	0.7019	0.0267	11.51 KB	0.12

EggMapper.Benchmarks.ColdStartBenchmark-report-github

Method	Mean	Error	StdDev	Min	Median	Max	Ratio	RatioSD	Rank	Gen0	Gen1	Allocated	Alloc Ratio
EggMapper	1.289 ms	1.710 ms	0.0937 ms	1.231 ms	1.238 ms	1.397 ms	1.00	0.09	1	3.9063	1.9531	95.33 KB	1.00
AutoMapper	3.871 ms	9.205 ms	0.5046 ms	3.435 ms	3.754 ms	4.424 ms	3.01	0.39	2	15.6250	7.8125	310.22 KB	3.25
Mapster	4.496 ms	9.104 ms	0.4990 ms	3.929 ms	4.695 ms	4.865 ms	3.50	0.40	2	39.0625	15.6250	757.6 KB	7.95

---

📝 Notes

• Each benchmark class is decorated with [MemoryDiagnoser] and [RankColumn].
• The global config (see src/EggMapper.Benchmarks/Program.cs) adds Min, Median, and Max columns.
• Manual is the hand-written baseline (ratio = 1.00). A ratio < 1 means faster than manual.
• Benchmarks run on GitHub-hosted runners — absolute times may vary between runs; focus on Ratio for comparisons.
• To reproduce locally:

  cd src/EggMapper.Benchmarks
  dotnet run --configuration Release -- --filter '*'