[labs/observers] Prevent failing in SSR

[a11delavar]

This PR makes observer controllers not to initialize the observers when the constructor is called in SSR environment, preventing a crash in SSR environment. Fixes #4590.

The isServer check being before window.xObserver check is intentional as window won't exist in Node. Also there is no need to warn the developer in SSR as opposed to when we are in the browser but the observer is not supported.

There is clean-up potential after #3386 has been merged, namely adding an abstract createObserver() method to the base class for all common browser observers and moving the isServer check to the base class and conditionally calling it.

[changeset-bot]

🦋 Changeset detected

Latest commit: 13e9db7

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

This PR includes changesets to release 1 package

Name	Type
@lit-labs/observers	Patch

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[github-actions]

📊 Tachometer Benchmark Results

Summary

⏳ Benchmarks are currently running. Results below are out of date.

nop-update

• this-change, tip-of-tree, previous-release: unsure 🔍 -3% - +6% (-0.36ms - +0.61ms)
  ^{this-change vs tip-of-tree}

render

• this-change: 45.11ms - 46.80ms
• this-change, tip-of-tree, previous-release: unsure 🔍 -4% - +3% (-0.68ms - +0.65ms)
  ^{this-change vs tip-of-tree}
• this-change, tip-of-tree, previous-release: unsure 🔍 -1% - +2% (-0.48ms - +0.79ms)
  ^{this-change vs tip-of-tree}
• this-change, tip-of-tree, previous-release: unsure 🔍 -3% - +1% (-0.83ms - +0.27ms)
  ^{this-change vs tip-of-tree}

update

• this-change: 473.51ms - 480.59ms
• this-change, tip-of-tree, previous-release: unsure 🔍 -5% - +7% (-1.81ms - +2.89ms)
  ^{this-change vs tip-of-tree}
• this-change, tip-of-tree, previous-release: unsure 🔍 -3% - +1% (-1.99ms - +0.68ms)
  ^{this-change vs tip-of-tree}
• this-change, tip-of-tree, previous-release: unsure 🔍 -1% - +2% (-3.34ms - +7.36ms)
  ^{this-change vs tip-of-tree}

update-reflect

• this-change: 482.76ms - 490.39ms
• this-change, tip-of-tree, previous-release: unsure 🔍 -1% - +1% (-5.66ms - +5.09ms)
  ^{this-change vs tip-of-tree}

Results

⏳ Benchmarks are currently running. Results below are out of date.

this-change

• Browser: chrome-headless 122.0.6261.128
• Sample size: 50
• Built by: Benchmarks #6159

• Commit: 196a8d4

render

Version	Avg time	vs
	45.11ms - 46.80ms	-

update

Version	Avg time	vs
	473.51ms - 480.59ms	-

update-reflect

Version	Avg time	vs
	482.76ms - 490.39ms	-

this-change, tip-of-tree, previous-release

• Browser: chrome-headless 122.0.6261.128
• Sample size: 30
• Built by: Benchmarks #6159

• Commit: 196a8d4

render

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	18.30ms - 19.17ms	-	unsure 🔍 -4% - +3% -0.68ms - +0.65ms	unsure 🔍 -5% - +2% -0.88ms - +0.43ms
tip-of-tree tip-of-tree	18.25ms - 19.25ms	unsure 🔍 -3% - +4% -0.65ms - +0.68ms	-	unsure 🔍 -5% - +3% -0.92ms - +0.49ms
previous-release previous-release	18.47ms - 19.46ms	unsure 🔍 -2% - +5% -0.43ms - +0.88ms	unsure 🔍 -3% - +5% -0.49ms - +0.92ms	-

update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	38.12ms - 41.41ms	-	unsure 🔍 -5% - +7% -1.81ms - +2.89ms	unsure 🔍 -8% - +4% -3.38ms - +1.56ms
tip-of-tree tip-of-tree	37.54ms - 40.91ms	unsure 🔍 -7% - +5% -2.89ms - +1.81ms	-	unsure 🔍 -10% - +2% -3.95ms - +1.04ms
previous-release previous-release	38.84ms - 42.52ms	unsure 🔍 -4% - +9% -1.56ms - +3.38ms	unsure 🔍 -3% - +10% -1.04ms - +3.95ms	-

nop-update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	10.80ms - 11.44ms	-	unsure 🔍 -3% - +6% -0.36ms - +0.61ms	unsure 🔍 -6% - +3% -0.62ms - +0.33ms
tip-of-tree tip-of-tree	10.64ms - 11.35ms	unsure 🔍 -5% - +3% -0.61ms - +0.36ms	-	unsure 🔍 -7% - +2% -0.78ms - +0.23ms
previous-release previous-release	10.92ms - 11.62ms	unsure 🔍 -3% - +6% -0.33ms - +0.62ms	unsure 🔍 -2% - +7% -0.23ms - +0.78ms	-

this-change, tip-of-tree, previous-release

• Browser: chrome-headless 122.0.6261.128
• Sample size: 50
• Built by: Benchmarks #6159

• Commit: 196a8d4

render

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	33.18ms - 34.09ms	-	unsure 🔍 -1% - +2% -0.48ms - +0.79ms	unsure 🔍 -3% - +2% -0.86ms - +0.73ms
tip-of-tree tip-of-tree	33.03ms - 33.92ms	unsure 🔍 -2% - +1% -0.79ms - +0.48ms	-	unsure 🔍 -3% - +2% -1.01ms - +0.57ms
previous-release previous-release	33.04ms - 34.35ms	unsure 🔍 -2% - +3% -0.73ms - +0.86ms	unsure 🔍 -2% - +3% -0.57ms - +1.01ms	-

update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	68.36ms - 69.60ms	-	unsure 🔍 -3% - +1% -1.99ms - +0.68ms	unsure 🔍 -1% - +1% -0.91ms - +1.01ms
tip-of-tree tip-of-tree	68.45ms - 70.82ms	unsure 🔍 -1% - +3% -0.68ms - +1.99ms	-	unsure 🔍 -1% - +3% -0.69ms - +2.10ms
previous-release previous-release	68.20ms - 69.66ms	unsure 🔍 -1% - +1% -1.01ms - +0.91ms	unsure 🔍 -3% - +1% -2.10ms - +0.69ms	-

this-change, tip-of-tree, previous-release

• Browser: chrome-headless 122.0.6261.128
• Sample size: 50
• Built by: Benchmarks #6159

• Commit: 196a8d4

render

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	30.51ms - 31.29ms	-	unsure 🔍 -3% - +1% -0.83ms - +0.27ms	unsure 🔍 -3% - +0% -0.83ms - +0.15ms
tip-of-tree tip-of-tree	30.80ms - 31.57ms	unsure 🔍 -1% - +3% -0.27ms - +0.83ms	-	unsure 🔍 -2% - +1% -0.54ms - +0.42ms
previous-release previous-release	30.96ms - 31.53ms	unsure 🔍 -0% - +3% -0.15ms - +0.83ms	unsure 🔍 -1% - +2% -0.42ms - +0.54ms	-

update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	480.91ms - 489.55ms	-	unsure 🔍 -1% - +2% -3.34ms - +7.36ms	unsure 🔍 -1% - +1% -6.80ms - +5.09ms
tip-of-tree tip-of-tree	480.07ms - 486.39ms	unsure 🔍 -2% - +1% -7.36ms - +3.34ms	-	unsure 🔍 -2% - +0% -8.03ms - +2.30ms
previous-release previous-release	482.01ms - 490.18ms	unsure 🔍 -1% - +1% -5.09ms - +6.80ms	unsure 🔍 -0% - +2% -2.30ms - +8.03ms	-

update-reflect

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	490.68ms - 498.77ms	-	unsure 🔍 -1% - +1% -5.66ms - +5.09ms	unsure 🔍 -1% - +1% -6.25ms - +6.04ms
tip-of-tree tip-of-tree	491.46ms - 498.56ms	unsure 🔍 -1% - +1% -5.09ms - +5.66ms	-	unsure 🔍 -1% - +1% -5.65ms - +6.01ms
previous-release previous-release	490.20ms - 499.46ms	unsure 🔍 -1% - +1% -6.04ms - +6.25ms	unsure 🔍 -1% - +1% -6.01ms - +5.65ms	-

_{tachometer-reporter-action v2 for Benchmarks}

[justinfagnani]

Looks good to me. @sorvell wdyt?

[github-actions]

The size of lit-html.js and lit-core.min.js are as expected.

[justinfagnani]

There's an important unresolved comment now

[augustjk]

Thanks!

[MrHBS]

What is left here guys?

[justinfagnani]

Thanks!