Use Symbol.for in dev mode

[rictic]

This makes it much easier to maintain state for an element during HMR because keys stay the same across different versions of the class.

[changeset-bot]

🦋 Changeset detected

Latest commit: 49a53d2

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 28 packages

Name	Type
@lit/reactive-element	Patch
@lit-internal/benchmarks	Patch
lit-element	Patch
lit	Patch
@lit/localize	Patch
@lit-labs/context	Patch
@lit-labs/observers	Patch
@lit-labs/scoped-registry-mixin	Patch
@lit-labs/ssr-client	Patch
@lit-labs/ssr	Patch
@lit-labs/task	Patch
@lit/lit-starter-js	Patch
@lit/lit-starter-ts	Patch
@lit/localize-tools	Patch
@lit-labs/eleventy-plugin-lit	Patch
@lit-labs/motion	Patch
@lit-labs/router	Patch
@lit-labs/ssr-react	Patch
@lit-labs/testing	Patch
@lit-labs/virtualizer	Patch
@lit-internal/test-element-a	Patch
@lit-internal/localize-examples-runtime-js	Patch
@lit-internal/localize-examples-runtime-ts	Patch
@lit-internal/localize-examples-transform-js	Patch
@lit-internal/localize-examples-transform-ts	Patch
@lit-labs/cli-localize	Patch
@lit-labs/cli	Patch
@lit-labs/nextjs	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions]

📊 Tachometer Benchmark Results

Summary

nop-update

• lit-html-kitchen-sink: unsure 🔍 -14% - +7% (-2.38ms - +1.31ms)
  ^{this-change vs tip-of-tree}

render

• lit-element-list: 74.32ms - 79.24ms
• lit-html-kitchen-sink: unsure 🔍 -10% - +6% (-3.53ms - +2.05ms)
  ^{this-change vs tip-of-tree}
• lit-html-repeat: unsure 🔍 -4% - +6% (-0.44ms - +0.66ms)
  ^{this-change vs tip-of-tree}
• lit-html-template-heavy: unsure 🔍 -4% - +2% (-2.35ms - +1.13ms)
  ^{this-change vs tip-of-tree}
• reactive-element-list: slower ❌ 0% - 7% (0.16ms - 3.56ms)
  ^{this-change vs tip-of-tree}

update

• lit-element-list: 770.40ms - 784.61ms
• lit-html-kitchen-sink: unsure 🔍 -9% - +5% (-7.16ms - +3.90ms)
  ^{this-change vs tip-of-tree}
• lit-html-repeat: unsure 🔍 -3% - +1% (-10.01ms - +1.63ms)
  ^{this-change vs tip-of-tree}
• lit-html-template-heavy: unsure 🔍 -3% - +1% (-2.95ms - +0.89ms)
  ^{this-change vs tip-of-tree}
• reactive-element-list: unsure 🔍 -0% - +1% (-0.78ms - +11.36ms)
  ^{this-change vs tip-of-tree}

update-reflect

• lit-element-list: 744.61ms - 751.57ms
• reactive-element-list: unsure 🔍 -1% - +0% (-7.08ms - +2.92ms)
  ^{this-change vs tip-of-tree}

Results

lit-element-list

• Browser: chrome-headless 112.0.5615.49
• Sample size: 50
• Built by: Benchmarks #4656

• Commit: 2d042da

render

Version	Avg time	vs
	74.32ms - 79.24ms	-

update

Version	Avg time	vs
	770.40ms - 784.61ms	-

update-reflect

Version	Avg time	vs
	744.61ms - 751.57ms	-

lit-html-kitchen-sink

• Browser: chrome-headless 112.0.5615.49
• Sample size: 30
• Built by: Benchmarks #4656

• Commit: 2d042da

render

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	31.58ms - 35.14ms	-	unsure 🔍 -10% - +6% -3.53ms - +2.05ms	unsure 🔍 -7% - +7% -2.24ms - +2.45ms
tip-of-tree tip-of-tree	31.95ms - 36.25ms	unsure 🔍 -6% - +11% -2.05ms - +3.53ms	-	unsure 🔍 -5% - +11% -1.80ms - +3.48ms
previous-release previous-release	31.73ms - 34.79ms	unsure 🔍 -7% - +7% -2.45ms - +2.24ms	unsure 🔍 -10% - +5% -3.48ms - +1.80ms	-

update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	74.60ms - 81.86ms	-	unsure 🔍 -9% - +5% -7.16ms - +3.90ms	unsure 🔍 -8% - +5% -6.08ms - +3.95ms
tip-of-tree tip-of-tree	75.69ms - 84.03ms	unsure 🔍 -5% - +9% -3.90ms - +7.16ms	-	unsure 🔍 -6% - +8% -4.85ms - +5.98ms
previous-release previous-release	75.84ms - 82.75ms	unsure 🔍 -5% - +8% -3.95ms - +6.08ms	unsure 🔍 -7% - +6% -5.98ms - +4.85ms	-

nop-update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	15.44ms - 17.38ms	-	unsure 🔍 -14% - +7% -2.38ms - +1.31ms	unsure 🔍 -6% - +9% -0.97ms - +1.41ms
tip-of-tree tip-of-tree	15.38ms - 18.52ms	unsure 🔍 -8% - +15% -1.31ms - +2.38ms	-	unsure 🔍 -6% - +15% -0.96ms - +2.48ms
previous-release previous-release	15.50ms - 16.89ms	unsure 🔍 -9% - +6% -1.41ms - +0.97ms	unsure 🔍 -14% - +5% -2.48ms - +0.96ms	-

lit-html-repeat

• Browser: chrome-headless 112.0.5615.49
• Sample size: 30
• Built by: Benchmarks #4656

• Commit: 2d042da

render

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	10.20ms - 10.82ms	-	unsure 🔍 -4% - +6% -0.44ms - +0.66ms	unsure 🔍 -4% - +4% -0.46ms - +0.46ms
tip-of-tree tip-of-tree	9.95ms - 10.85ms	unsure 🔍 -6% - +4% -0.66ms - +0.44ms	-	unsure 🔍 -6% - +4% -0.68ms - +0.46ms
previous-release previous-release	10.17ms - 10.86ms	unsure 🔍 -4% - +4% -0.46ms - +0.46ms	unsure 🔍 -4% - +7% -0.46ms - +0.68ms	-

update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	283.12ms - 289.66ms	-	unsure 🔍 -3% - +1% -10.01ms - +1.63ms	unsure 🔍 -1% - +2% -2.90ms - +6.81ms
tip-of-tree tip-of-tree	285.77ms - 295.39ms	unsure 🔍 -1% - +4% -1.63ms - +10.01ms	-	slower ❌ 0% - 4% 0.14ms - 12.15ms
previous-release previous-release	280.84ms - 288.02ms	unsure 🔍 -2% - +1% -6.81ms - +2.90ms	faster ✔ 0% - 4% 0.14ms - 12.15ms	-

lit-html-template-heavy

• Browser: chrome-headless 112.0.5615.49
• Sample size: 50
• Built by: Benchmarks #4656

• Commit: 2d042da

render

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	54.64ms - 57.39ms	-	unsure 🔍 -4% - +2% -2.35ms - +1.13ms	unsure 🔍 -6% - +1% -3.26ms - +0.63ms
tip-of-tree tip-of-tree	55.56ms - 57.69ms	unsure 🔍 -2% - +4% -1.13ms - +2.35ms	-	unsure 🔍 -4% - +2% -2.45ms - +1.03ms
previous-release previous-release	55.96ms - 58.71ms	unsure 🔍 -1% - +6% -0.63ms - +3.26ms	unsure 🔍 -2% - +4% -1.03ms - +2.45ms	-

update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	109.68ms - 112.36ms	-	unsure 🔍 -3% - +1% -2.95ms - +0.89ms	unsure 🔍 -2% - +1% -2.14ms - +1.21ms
tip-of-tree tip-of-tree	110.67ms - 113.42ms	unsure 🔍 -1% - +3% -0.89ms - +2.95ms	-	unsure 🔍 -1% - +2% -1.14ms - +2.27ms
previous-release previous-release	110.48ms - 112.49ms	unsure 🔍 -1% - +2% -1.21ms - +2.14ms	unsure 🔍 -2% - +1% -2.27ms - +1.14ms	-

reactive-element-list

• Browser: chrome-headless 112.0.5615.49
• Sample size: 50
• Built by: Benchmarks #4656

• Commit: 2d042da

render

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	52.97ms - 55.63ms	-	slower ❌ 0% - 7% 0.16ms - 3.56ms	unsure 🔍 -1% - +5% -0.68ms - +2.73ms
tip-of-tree tip-of-tree	51.38ms - 53.51ms	faster ✔ 0% - 6% 0.16ms - 3.56ms	-	unsure 🔍 -4% - +1% -2.34ms - +0.68ms
previous-release previous-release	52.20ms - 54.35ms	unsure 🔍 -5% - +1% -2.73ms - +0.68ms	unsure 🔍 -1% - +4% -0.68ms - +2.34ms	-

update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	805.85ms - 815.29ms	-	unsure 🔍 -0% - +1% -0.78ms - +11.36ms	unsure 🔍 -1% - +1% -4.49ms - +10.14ms
tip-of-tree tip-of-tree	801.46ms - 809.10ms	unsure 🔍 -1% - +0% -11.36ms - +0.78ms	-	unsure 🔍 -1% - +1% -9.24ms - +4.30ms
previous-release previous-release	802.15ms - 813.33ms	unsure 🔍 -1% - +1% -10.14ms - +4.49ms	unsure 🔍 -1% - +1% -4.30ms - +9.24ms	-

update-reflect

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	791.94ms - 799.22ms	-	unsure 🔍 -1% - +0% -7.08ms - +2.92ms	unsure 🔍 -1% - +0% -9.89ms - +1.55ms
tip-of-tree tip-of-tree	794.23ms - 801.09ms	unsure 🔍 -0% - +1% -2.92ms - +7.08ms	-	unsure 🔍 -1% - +0% -7.68ms - +3.51ms
previous-release previous-release	795.33ms - 804.16ms	unsure 🔍 -0% - +1% -1.55ms - +9.89ms	unsure 🔍 -0% - +1% -3.51ms - +7.68ms	-

_{tachometer-reporter-action v2 for Benchmarks}