### Setup apt-get for Dart SDK on Linux

Source: https://github.com/dart-lang/sdk/blob/main/docs/Installing-beta-and-dev-releases-using-package-managers.md

One-time setup commands for using apt-get to install Dart SDK packages on Linux. This includes updating package lists, installing dependencies, and adding Dart's signing key and repository lists.

```bash
$ apt-get -q update && apt-get install --no-install-recommends -y -q gnupg2 curl git ca-certificates apt-transport-https openssh-client && \
  curl https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add - && \
  curl https://storage.googleapis.com/download.dartlang.org/linux/debian/dart_stable.list > /etc/apt/sources.list.d/dart_stable.list && \
  curl https://storage.googleapis.com/download.dartlang.org/linux/debian/dart_testing.list > /etc/apt/sources.list.d/dart_testing.list && \
  curl https://storage.googleapis.com/download.dartlang.org/linux/debian/dart_unstable.list > /etc/apt/sources.list.d/dart_unstable.list && \
  apt-get update
```

--------------------------------

### Install Dart SDK channels with apt-get

Source: https://github.com/dart-lang/sdk/blob/main/docs/Installing-beta-and-dev-releases-using-package-managers.md

Commands to install different channels of the Dart SDK on Linux using apt-get after the initial setup.

```bash
$ apt-get -t unstable install dart # installs the latest dev dart
$ apt-get -t testing install dart # installs the latest beta dart
$ apt-get -t stable install dart # installs the latest stable dart
$ apt-get install dart # installs the latest version of dart
```

--------------------------------

### Install snapshot_analysis CLI

Source: https://github.com/dart-lang/sdk/blob/main/pkg/vm_snapshot_analysis/README.md

Install the `snapshot_analysis` command-line tool globally using `pub global activate`.

```console
$ pub global activate vm_snapshot_analysis
```

--------------------------------

### Install Uprobe for Allocation Profiling

Source: https://github.com/dart-lang/sdk/blob/main/runtime/tools/profiling/README.md

Install a uprobe specifically for the `AllocationProbePoint` to capture allocation-related data. Requires root privileges.

```bash
sudo $(which dart) runtime/tools/profiling/bin/set_uprobe.dart alloc AllocationProbePoint test.aot
```

--------------------------------

### Debug Dart VM with GDB and QEMU

Source: https://github.com/dart-lang/sdk/blob/main/runtime/docs/qemu.md

Install GDB for multi-architecture debugging. Start the Dart VM under QEMU with GDB server enabled, then connect to it using GDB, setting the system root and continuing execution.

```bash
$ sudo apt install qemu-user libc6-arm64-cross gdb-multiarch
$ QEMU_LD_PREFIX=/usr/aarch64-linux-gnu/ qemu-aarch4 -g 9090 out/DebugXARM64/dartvm hello.dart.dill
```

```gdb
(gdb) set sysroot /usr/aarch64-linux-gnu/
(gdb) target remote localhost:9090
(gdb) continue
```

--------------------------------

### Start Android Emulator

Source: https://github.com/dart-lang/sdk/blob/main/docs/Building-the-Dart-VM-for-Android.md

Launch an Android emulator using the android_finder.py script. The -b flag ensures an emulator is started if none are available for the specified ABI.

```bash
$ runtime/tools/android_finder.py -a {armeabi-v7a, x86} -b
```

--------------------------------

### Install build tools on Linux

Source: https://github.com/dart-lang/sdk/blob/main/docs/Building.md

Installs essential build tools for Dart SDK on Linux systems. Ensure git, python3, curl, and xz-utils are installed before proceeding.

```bash
sudo apt-get install git python3 curl xz-utils
```

--------------------------------

### Install Python Dependencies

Source: https://github.com/dart-lang/sdk/blob/main/runtime/tools/wiki/README.md

Install all necessary Python dependencies for the wiki rendering tools using pip. This command should be run after cloning the repository.

```console
pip3 install coloredlogs jinja2 markdown aiohttp watchdog pymdown-extensions pygments
```

--------------------------------

### Start HTTP Server for Browser Tests

Source: https://github.com/dart-lang/sdk/blob/main/docs/Building.md

Use this command to start a local HTTP server for debugging browser test failures. The exact path may vary.

```bash
To retest, run:  /usr/local/[...]/dart/tools/testing/bin/linux/dart /usr/local/[...]/dart/tools/testing/dart/http_server.dart ...
```

--------------------------------

### Build with Scons

Source: https://github.com/dart-lang/sdk/blob/main/third_party/double-conversion/README.md

Use 'scons install' to build and install the static and shared libraries. The DESTDIR option can change the target installation directory.

```bash
scons install
```

```bash
scons DESTDIR=alternative_directory install
```

--------------------------------

### Install beta Dart SDK with Homebrew

Source: https://github.com/dart-lang/sdk/blob/main/docs/Installing-beta-and-dev-releases-using-package-managers.md

Use this command to install the latest beta release of the Dart SDK on macOS using Homebrew.

```bash
brew install dart-beta
```

--------------------------------

### Install specific Dart SDK version with apt-get

Source: https://github.com/dart-lang/sdk/blob/main/docs/Installing-beta-and-dev-releases-using-package-managers.md

Use this command to install a specific version of the Dart SDK on Linux using apt-get.

```bash
$ apt-get install dart=2.9.0-4.0.dev-1
```

--------------------------------

### Dart Example Code Block

Source: https://github.com/dart-lang/sdk/blob/main/pkg/analyzer/doc/implementation/diagnostics.md

Illustrates how to format a Dart code example within documentation, including language specification and highlight markers.

```dart
```dart
// Example code here
[!diagnostic region!]
```
```

--------------------------------

### LayeredPicture get guid() Getter

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Returns the unique identifier (guid) of the LayeredPicture.

```javascript
get guid(){return this.guid_;} 
```

--------------------------------

### Get Annotation by GUID

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Retrieves an annotation object using its unique GUID.

```javascript
getAnnotationByGUID(guid){return this.annotationsByGuid\_\\[guid\\];}
```

--------------------------------

### Build release VM and run FFI unit tests

Source: https://github.com/dart-lang/sdk/blob/main/docs/Building.md

Before running tests, use `build.py` to build the 'most' and 'run_ffi_unit_tests' targets. This example builds the release version of the VM.

```bash
./tools/build.py --mode release most run_ffi_unit_tests
```

--------------------------------

### Run Wiki Webserver for Development

Source: https://github.com/dart-lang/sdk/blob/main/runtime/tools/wiki/README.md

Use this command to start a local webserver for developing wiki pages. Ensure you are in the root directory of the SDK.

```shell
runtime/tools/wiki/build/build.py
```

--------------------------------

### Get Start Angle

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Accessor function to retrieve the start angle of a radial element.

```javascript
function ro(n){return n.startAngle}
```

--------------------------------

### Begin Hosting Context

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Pushes the current component onto the host stack, initiating a hosting context for child elements.

```javascript
this._beginHosting=function(){Polymer.Base._hostStack.push(this);if(!this._clients){this._clients=[];}}
```

--------------------------------

### PictureSnapshot get guid() Getter

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Returns the unique identifier (guid) of the PictureSnapshot, which is delegated to the underlying Picture object.

```javascript
get guid(){return this.picture_.guid;}
```

--------------------------------

### JNIgen Configuration Example

Source: https://github.com/dart-lang/sdk/blob/main/docs/gsoc/Dart-GSoC-2024-Project-Ideas.md

An example of a jnigen.yaml configuration file used for generating Dart bindings from Java code. This file specifies build settings and dependencies for the JNIgen process.

```yaml
targets:
  - name: cronet_http
    sources:
      - src/java
    package: org.chromium.cronet_http
    # ... other configurations
```

--------------------------------

### Patch File Syntax Example

Source: https://github.com/dart-lang/sdk/blob/main/pkg/front_end/testcases/dartino/README.md

Demonstrates the basic syntax of a .patch file, including conditional blocks and alternatives.

```text
==> file.txt.patch <==
first
<<<< "ex1"
v1
==== "ex2"
v2
==== "ex2"
v3
>>>>
last
```

--------------------------------

### Get Frame Start Time

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Determines the start time of a frame, considering pre-traversal work ranges. It finds the closest pre-traversal work range that starts before the traversal.

```javascript
function getFrameStartTime(traversalStart,preTraversalWorkRanges){
const preTraversalWorkRange=tr.b.findClosestIntervalInSortedIntervals(preTraversalWorkRanges,function(range){return range.start;},function(range){return range.end;},traversalStart,3);
if(preTraversalWorkRange){
return preTraversalWorkRange.start;
}
return traversalStart;
}
```

--------------------------------

### Build a sample project to interop with a Go library

Source: https://github.com/dart-lang/sdk/blob/main/docs/gsoc/Dart-GSoC-2023-Project-Ideas.md

This is a suggested sample project for the GOgen idea. It involves building a small project to demonstrate interop with a Go library.

```dart
Build a small sample project where you interop with a Go library. (2) Build a prototype for generating the bindings for that library, and (3) use a Go parser to generate those bindings.
```

--------------------------------

### Get V8 Source Code and Build

Source: https://github.com/dart-lang/sdk/blob/main/pkg/dart2wasm/docs/v8.md

Use this command sequence to fetch the V8 source code and perform an initial build. Ensure `depot_tools` is in your PATH.

```bash
% mkdir v8-gclient && cd v8-gclient
v8-gclient % fetch v8 && cd v8
v8-gclient/v8 % tools/dev/gm.py x64.release d8 wami
...
```

--------------------------------

### Compare Events by Time and GUID in JavaScript

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Compares two event objects based on their start and end times, and then by GUID if available. This is crucial for stable sorting of events.

```javascript
function compareEvents(x,y){
if(x.start!==y.start){
return x.start-y.start;
}
if(x.end!==y.end){
return x.end-y.end;
}
if(x.guid&&y.guid){
return x.guid-y.guid;
}
return 0;
}
```

--------------------------------

### Initialize Help Button

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Sets up the help button, which toggles the visibility of an overlay containing help information. The overlay is created as a tr.ui.b.Overlay element.

```javascript
initHelpButton_(){
const helpButtonEl=this.$.view_help_button;
const dlg=new tr.ui.b.Overlay();
dlg.title='Chrome Tracing Help';
dlg.visible=false;
dlg.appendChild(document.createElement('tr-ui-timeline-view-help-overlay'));
function onClick(e){
dlg.visible=!dlg.visible;
e.stopPropagation();
}
helpButtonEl.addEventListener('click',onClick.bind(this));
}
```

--------------------------------

### Get Navigation Start Timestamps

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Extracts navigation start timestamps from trace events. Filters events by title 'navigationStart' and category 'blink.user_timing'. Requires a renderer helper object.

```javascript
function getNavStartTimestamps(rendererHelper) {
  const navStartTimestamps = [];
  for (const e of rendererHelper.mainThread.sliceGroup.childEvents()) {
    if (hasTitleAndCategory(e, 'navigationStart', 'blink.user_timing')) {
      navStartTimestamps.push(e.start);
    }
  }
  return navStartTimestamps;
}
```

--------------------------------

### Get SPA Navigation Start Candidates in Dart

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Identifies potential SPA navigation start events from both renderer and browser helpers. It filters events based on specific titles and categories.

```dart
const HANDLE_INPUT_EVENT_TITLE='WebViewImpl::handleInputEvent';function getSpaNavigationStartCandidates_(rendererHelper,browserHelper){const isNavStartEvent=e=>{if(e.title===HANDLE_INPUT_EVENT_TITLE&&e.args.type==='MouseUp'){return true;} return e.title==='NavigationControllerImpl::GoToIndex';};return[...rendererHelper.mainThread.sliceGroup.getDescendantEvents(),...browserHelper.mainThread.sliceGroup.getDescendantEvents()].filter(isNavStartEvent);}
```

--------------------------------

### Setup Component Configuration

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Initializes the component's configuration object and handler array. Use when creating a new component instance.

```javascript
this._setupConfigure:function(initialConfig){this._config={};this._handlers=[]this._aboveConfig=null;if(initialConfig){for(var i in initialConfig){if(initialConfig[i]!==undefined){this._config[i]=initialConfig[i];}}}}
```

--------------------------------

### D3.js Transition Delay

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Sets or gets the delay before a transition starts. Can be a fixed value or a function.

```javascript
Ns.delay=function(n){var t=this.id;return R(this,"function"==typeof n?function(e,r,u){e.__transition__[t].delay=+n.call(e,e.__data__,r,u)}:(n=+n,function(e){e.__transition__[t].delay=n}))}
```

--------------------------------

### Serve Observatory

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/README.md

Execute this command to serve the Observatory tool. Use the --launch flag to automatically open it in Chrome.

```bash
observatory
```

```bash
observatory --launch
```

--------------------------------

### Get Field Name Node

Source: https://github.com/dart-lang/sdk/blob/main/pkg/analysis_server/doc/implementation/quick_fix.md

Retrieves the AST node for the field name. This is the starting point for fix computation.

```dart
var fieldName = node;
```

--------------------------------

### Test RISC-V 32 with QEMU

Source: https://github.com/dart-lang/sdk/blob/main/runtime/docs/riscv32.md

Configure QEMU's dynamic linker prefix using QEMU_LD_PREFIX and then use test.py to run tests for riscv32 architecture with QEMU. This example specifically targets FFI tests and generates ELF snapshots.

```bash
export QEMU_LD_PREFIX="$RV32_TOOLCHAIN/riscv32-buildroot-linux-gnu/sysroot"
./tools/test.py -mrelease -ariscv32 --use-qemu --gen-snapshot-format=elf -cdartk,dartkp -t900 ffi
```

--------------------------------

### Get SPA Navigation Event to Navigation Start Map in Dart

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Maps SPA navigation events to their corresponding navigation start candidates and input latency events. This function is part of a larger process for analyzing navigation performance.

```dart
function getSpaNavigationEventToNavigationStartMap_(rendererHelper,browserHelper){const mainThread=rendererHelper.mainThread;const spaNavEvents=getSpaNavigationEvents_(rendererHelper);const navStartCandidates=getSpaNavigationStartCandidates_(rendererHelper,browserHelper).sort(tr.importer.compareEvents);const spaNavEventToNavStartCandidateMap=findPrecedingEvents_(spaNavEvents,navStartCandidates);const inputLatencyEventByBindIdMap=getInputLatencyEventByBindIdMap_(browserHelper);const spaNavEventToNavStartEventMap=new Map();for(const[spaNavEvent,navStartCandidate]of spaNavEventToNavStartCandidateMap){if(navStart
```

--------------------------------

### Sort Rasterizer Slices

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Sorts rasterizer slices based on their start time and then by GUID. This is a utility function for organizing rasterization tasks.

```dart
sortRasterizerSlices(rasterWorkerThreads,sortedRasterizerSlices){rasterWorkerThreads.forEach(function(rasterizer){Array.prototype.push.apply(sortedRasterizerSlices,rasterizer.sliceGroup.slices);},this);sortedRasterizerSlices.sort(function(a,b){if(a.start!==b.start){return a.start-b.start;} return a.guid-b.guid;});}
```

--------------------------------

### Launch Coverage Server Tool

Source: https://github.com/dart-lang/sdk/blob/main/pkg/dart2js_info/README.md

Start the coverage server tool to serve the JavaScript code of your application. This is a step in setting up coverage analysis.

```bash
$ dart bin/tools.dart coverage_server main.dart.js
```

--------------------------------

### Find Next Slice After Timestamp in Dart

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Finds the next slice that starts after a given timestamp, optionally considering a reference GUID to skip slices.

```dart
findNextSliceAfter(ts,refGuid){let i=tr.b.findLowIndexInSortedArray(this.slices,getSliceLo,ts);if(i===this.slices.length){return undefined;} for(;i<this.slices.length;i++){const slice=this.slices[i];if(slice.start>ts)return slice;if(slice.guid<=refGuid)continue;return slice;} return undefined;}
```

--------------------------------

### Prepare Local Web Server Document Root

Source: https://github.com/dart-lang/sdk/blob/main/pkg/compiler/test/codesize/swarm/appengine/dev.html

Navigate to the web server's document root, remove old data if necessary, unzip new data, and set read/write permissions. This prepares the directory for serving local files.

```bash
pushd /Library/WebServer/Document
# If you are replacing old data:
# rm -rf data/
unzip ~/Downloads/CannedData.zip
chmod -R +rw data
```

--------------------------------

### Layout: Get Deepest Leftmost Node

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Recursively finds the leftmost node at the deepest level of a tree. Useful for determining the starting point of a layout.

```javascript
function Ni(n){var t=n.children;return t&&t.length?Ni(t[0]):n}
```

--------------------------------

### Dart FFI SQLite Error Example

Source: https://github.com/dart-lang/sdk/blob/main/samples/ffi/sqlite/README.md

This error message indicates that the SQLite dynamic library could not be loaded. Ensure the SQLite development library is installed on your system.

```text
Unhandled exception:
Invalid argument(s): Failed to load dynamic library (126)
#0      _open (dart:ffi-patch/ffi_dynamic_library_patch.dart:13:55)
#1      new DynamicLibrary.open (dart:ffi-patch/ffi_dynamic_library_patch.dart:22:12)
```

--------------------------------

### Install QEMU and Cross-Architecture Libraries

Source: https://github.com/dart-lang/sdk/blob/main/docs/Building-Dart-SDK-for-ARM-or-RISC-V.md

Installs QEMU user-mode emulator and necessary cross-architecture C libraries for testing Dart VM on different architectures without hardware. This is required for running tests using QEMU.

```bash
$ sudo apt install qemu-user libc6-armhf-cross libc6-arm64-cross libc6-riscv64-cross
```

--------------------------------

### List Available Benchmarks

Source: https://github.com/dart-lang/sdk/blob/main/pkg/analysis_server/benchmark/readme.md

Run this command to see a list of all available benchmarks.

```bash
dart benchmark/benchmarks.dart list
```

--------------------------------

### EventRef Class Definition

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

A lightweight reference class for events, storing essential details like stable ID, title, start time, and duration. It generates a unique GUID for each instance.

```javascript
'use strict';
tr.exportTo('tr.v.d',function(){
class EventRef{
constructor(event){
this.stableId=event.stableId;
this.title=event.title;
this.start=event.start;
this.duration=event.duration;
this.end=this.start+this.duration;
this.guid=tr.b.GUID.allocateSimple();
}
}
return{EventRef,};
});
```

--------------------------------

### Get Event Endpoints

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Generates an array of endpoint objects (time and type) for a given list of events, marking the start and end of each event. Used for network and long task analysis.

```javascript
function getEndpoints_(events,startType,endType){const endpoints=[];for(const event of events){endpoints.push({time:event.start,type:startType});endpoints.push({time:event.end,type:endType});} return endpoints;}
```

--------------------------------

### Run Dart VM with QEMU

Source: https://github.com/dart-lang/sdk/blob/main/runtime/docs/qemu.md

Install necessary packages and build the Dart VM for ARM64. Then, run a Dart program using QEMU, specifying the QEMU interpreter and the path to the cross-architecture dynamic linker prefix.

```bash
$ sudo apt install qemu-user libc6-arm64-cross
$ tools/build.py --arch arm64 runtime runtime_precompiled
$ QEMU_LD_PREFIX=/usr/aarch64-linux-gnu/ qemu-aarch64 out/DebugXARM64/dartvm hello.dart.dill
```

--------------------------------

### Dart 'And' Combiner Node Example

Source: https://github.com/dart-lang/sdk/blob/main/pkg/compiler/doc/split_constraints.md

Demonstrates deferred loading with 'and' combiner logic where the order of loading libraries might vary. This setup allows Dart2js to merge shared code between 'step1a' and 'step1b' and their respective successors/predecessors.

```dart
import '...' deferred as step1a;
import '...' deferred as step1b;

do() {
  if (...) {
    step1a.loadLibrary().then((_) { step1b.loadLibrary().then(...) } );
  } else {
    step1b.loadLibrary().then((_) { step1a.loadLibrary().then(...) } );
  }
}
```

```yaml
  ...
  - type: and
    name: step1
    nodes:
      - step1a
      - step1b
  ...
```

--------------------------------

### Example Grouping Configuration YAML

Source: https://github.com/dart-lang/sdk/blob/main/pkg/dart2js_info/README.md

An example YAML file for configuring library grouping in the size split tool. It demonstrates various ways to define groups, including using regular expressions to extract names and specifying cluster indices.

```yaml
groups:
# This group shows the total size for all libraries that were loaded from
# file:// urls, it is shown in cluster #2, which happens to be the last
# cluster in this example before the totals are shown:
- name: "Loose files"
  regexp: "file://.*"
  cluster: 2

# This group shows the total size of all code loaded from packages:
- { name: "All packages", regexp: "package:.*", cluster: 2}

# This group shows the total size of all code loaded from core libraries:
- { name: "Core libs", regexp: "dart:.*", cluster: 2}

# This group shows the total size of all libraries in a single package. Here
# we omitted the `name` entry, instead we extract it from the regexp
# directly.  In this case, the name will be the package-name portion of the
# package-url (determined by group(1) of the regexp).
- { regexp: "package:([^/]*)", cluster: 1}

# The next two groups match the entire library url as the name of the group.
- regexp: "package:.*"
- regexp: "dart:.*"

# If your code lives under /my/project/dir, this will match any file loaded
from a file:// url, and we use as a name the relative path to it.
- regexp: "file:///my/project/dir/(.*)"
```

--------------------------------

### Get Lock Contention Alert

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Generates an alert for UI thread lock contention if the blocked duration exceeds 1 millisecond. Filters events by titles starting with 'Lock Contention on '. Requires associated events related to lock contention.

```javascript
AndroidAuditor.getLockContentionAlert_ = function(frame) {
  const events = frame.associatedEvents.filter(function(event) {
    return /^Lock Contention on /.test(event.title);
  });
  const blockedDuration = Statistics.sum(events, getDuration);
  if (blockedDuration < 1) return undefined;
  const start = Statistics.min(events, getStart);
  events.push(frame);
  return new Alert(AndroidAuditor.lockContentionAlertInfo_, start, events, {
    'Blocked duration': new Scalar(timeDurationInMs, blockedDuration)
  });
};
```

--------------------------------

### Install Specific Alpine Linux Sysroots

Source: https://github.com/dart-lang/sdk/blob/main/build/linux/alpine_sysroot_scripts/README.md

Specify the desired architectures when running the install script to customize the sysroot installation.

```sh
./build/linux/alpine_sysroot_scripts/install-sysroot.sh aarch64 riscv64 x86_64 ...
```

--------------------------------

### Build Wiki for Deployment

Source: https://github.com/dart-lang/sdk/blob/main/runtime/tools/wiki/README.md

Execute this command to build the wiki for deployment. This command also handles the generation of reference sections for C++ symbols and files if present in the markdown.

```shell
runtime/tools/wiki/build/build.py --deploy
```

--------------------------------

### Client Initialization with Experimental Commands

Source: https://github.com/dart-lang/sdk/blob/main/pkg/analysis_server/tool/lsp_spec/README.md

Clients must declare support for experimental commands during initialization by listing them in the 'experimental.commands' field of their capabilities.

```js
{
	// ... other client capabilities
	"experimental": {
		"commands": [
			"dart.goToLocation",
		]
	}
}
```

--------------------------------

### Fix Response Animation Starts

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Adjusts the start time of animation ProtoExpectations to align with the end time of intersecting response ProtoExpectations. Filters out impl frame events that start before the new animation start time.

```javascript
function fixResponseAnimationStarts(protoExpectations){protoExpectations.forEach(function(ape){if(ape.type!==ProtoExpectation.ANIMATION_TYPE){return;} protoExpectations.forEach(function(rpe){if(rpe.type!==ProtoExpectation.RESPONSE_TYPE){return;} if(!ape.containsTimestampInclusive(rpe.end)){return;} if(ape.containsTimestampInclusive(rpe.start)){return;} ape.start=rpe.end;if(ape.associatedEvents!==undefined){ape.associatedEvents=ape.associatedEvents.filter(e=>(!isImplFrameEvent(e)||e.start>=ape.start));}});});return protoExpectations;}
```

--------------------------------

### Initialize Binary Size Analysis UI

Source: https://github.com/dart-lang/sdk/blob/main/pkg/vm_snapshot_analysis/lib/src/assets/index.html

Initializes the UI for binary size analysis, setting up the subtitle and the D3 treemap visualization. Requires window.metadata to be defined.

```javascript
function init() {
 if (window.metadata !== undefined && window.metadata.subtitle) {
 document.getElementById('subtitle').innerHTML = ': ' + escape(metadata.subtitle);
 }
 initFilterOptions();
 treemap = new D3SymbolTreeMap( savedSettings.width,
 savedSettings.height,
 savedSettings.maxLevels);
 treemap.init();
}
```

--------------------------------

### Build Perfetto Tools

Source: https://github.com/dart-lang/sdk/blob/main/third_party/perfetto/README.md

Clone the Perfetto repository, checkout the required revision, install build dependencies, configure build arguments, and compile the protoc and protozero_plugin tools.

```bash
$ git clone https://github.com/google/perfetto
$ cd perfetto
$ git checkout $perfetto_rev_from_DEPS
$ tools/install-build-deps
$ gn args out/linux
$ ninja -C out/linux protoc protozero_plugin
```

--------------------------------

### streamListen Request Example

Source: https://github.com/dart-lang/sdk/blob/main/runtime/vm/service/service.md

Example of a streamListen RPC request, demonstrating how to provide parameters.

```APIDOC
## streamListen Request Example

### Description
Example of a streamListen RPC request, demonstrating how to provide parameters.

### Method
POST (typically)

### Endpoint
/

### Request Body Example
```json
{
  "jsonrpc": "2.0",
  "method": "streamListen",
  "params": {
    "streamId": "GC"
  },
  "id": "2"
}
```

### Parameters
- **jsonrpc** (string) - Required - Specifies the JSON-RPC protocol version.
- **method** (string) - Required - The name of the method to be invoked (e.g., "streamListen").
- **params** (object) - Required - An object containing named parameters for the method.
  - **streamId** (string) - Required - The identifier of the stream to listen to (e.g., "GC").
- **id** (string | number | null) - Required - An identifier established by the client to match the request with the response.
```

--------------------------------

### Run FFI Tests with QEMU

Source: https://github.com/dart-lang/sdk/blob/main/runtime/docs/qemu.md

Install cross-compilation packages for ARM and RISC-V. Build the Dart VM with snapshot generation for the simulator and runtime. Finally, execute FFI tests using the test runner, specifying QEMU, compilation modes, snapshot format, and architecture flags.

```bash
$ sudo apt install qemu-user libc6-armhf-cross libc6-arm64-cross libc6-riscv64-cross
$ ./tools/build.py --arch simarm_x64 gen_snapshot
$ ./tools/build.py --arch arm,arm64,riscv64,simarm64_arm64 runtime runtime_precompiled
$ ./tools/test.py --arch arm,arm64,riscv64,simarm64_arm64 --use-qemu --compiler dartk,dartkp --gen-snapshot-format elf --timeout 500 ffi
```

--------------------------------

### Dart Diagnostic Description Example

Source: https://github.com/dart-lang/sdk/blob/main/pkg/analyzer/doc/implementation/diagnostics.md

Example of a description for a Dart diagnostic, explaining when it's produced and why.

```dart
> The analyzer produces this diagnostic when an extension override doesn't
> have exactly one argument.

> The argument is the expression used to compute the value of `this` within the
> extension method, so there must be one argument.
```

--------------------------------

### Create Dart Test Script

Source: https://github.com/dart-lang/sdk/blob/main/docs/Building-the-Dart-VM-for-Android.md

Create a simple Dart script that prints 'Hello, world!' to the console. This script will be used to test the Dart VM on the emulator.

```bash
$ echo "main(){ print(\"Hello, world!\");}" >hello.dart
```

--------------------------------

### workspace/startLanguageServer

Source: https://github.com/dart-lang/sdk/blob/main/pkg/dartpad/doc/worker-protocol.md

Starts a language server instance for the workspace.

```APIDOC
## Method workspace/startLanguageServer

### Description
Start a language-server.

### Method
POST

### Endpoint
/workspace/startLanguageServer

### Parameters
#### Request Body
- **workspaceId** (number) - Required - The ID of the workspace.

### Response
#### Success Response (200)
- **languageServerId** (number) - Required - Identifier for the language-server just started.

```

--------------------------------

### Source File and Line Starts

Source: https://github.com/dart-lang/sdk/blob/main/pkg/dart2bytecode/docs/bytecode.md

Defines the structure for source files, including flags indicating the presence of line starts, source content, and const constructor coverage. It also details the encoding of line start offsets.

```dart
type SourceFile {
  UInt flags = (hasLineStarts, hasSource, hasConstConstructorCoverageFlag)
  PackedObject importUri;

  if hasLineStarts
    // Offset of line starts in ‘lineStarts’ section of BytecodeFile.
    UInt lineStartsOffset;

  if hasSource
    PackedString source;

  if hasConstConstructorCoverageFlag
    List<PackedObject> coveredConstConstructors;
}

type LineStarts {
  // Can be also treated as line lengths.
  List<UInt> deltaEncodedLineStarts;
}
```

--------------------------------

### Build with Bazel

Source: https://github.com/dart-lang/sdk/blob/main/third_party/double-conversion/README.md

Build the library or run unit tests using Bazel commands. The library is available through the Bazel Central Registry.

```bash
bazel build //:double-conversion
```

```bash
bazel test //:cctest
```

--------------------------------

### Install dartdoc tool

Source: https://github.com/dart-lang/sdk/blob/main/pkg/dart2js_info/DEVELOPER.md

Ensure the dartdoc tool is installed globally. This is required for generating API documentation.

```bash
pub global activate dartdoc
```

--------------------------------

### Build and Test Dart SDK (Precompilation)

Source: https://github.com/dart-lang/sdk/blob/main/docs/Testing-the-VM.md

Build and test the Dart SDK with precompilation enabled for faster startup times.

```bash
./tools/build.py -mrelease runtime_precompiled
```

```bash
./tools/test.py -mrelease -cprecompiler -rdart_precompiled
```

--------------------------------

### Ready Component Clients

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Iterates through the component's clients and calls their respective '_ready()' methods, ensuring they are initialized.

```javascript
this._readyClients=function(){this._beginDistribute();var c$=this._clients;if(c$){for(var i=0,l=c$.length,c;i<l&&(c=c$[i]);i++){c._ready();}} this._finishDistribute();}
```

--------------------------------

### Find Draw Slice within Time Range

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Locates the earliest 'draw' slice for a given application within a specified time window relative to a start time. It considers slices starting between MIN_DRAW_DELAY_IN_MS and MAX_DRAW_DELAY_IN_MS after the reference start time.

```javascript
function findDrawSlice(appName,startNotBefore,model){let drawSlice=undefined;const thread=findUIThread(findProcess(appName,model));if(thread===undefined)return undefined;for(const sliceId in thread.sliceGroup.slices){const slice=thread.sliceGroup.slices[sliceId];if(slice.start<startNotBefore+MIN_DRAW_DELAY_IN_MS||slice.start>startNotBefore+MAX_DRAW_DELAY_IN_MS)continue;if(slice.title!=='draw')continue;if(drawSlice===undefined||slice.start<drawSlice.start){drawSlice=slice;}} return drawSlice;}
```

--------------------------------

### Continue a code example across multiple blocks

Source: https://github.com/dart-lang/sdk/blob/main/tools/verify_docs/README.md

Mark subsequent code blocks as 'continued' to indicate they are part of the preceding code example. This allows for splitting longer examples while ensuring they are analyzed as a single unit. A 'continued' block cannot have other flags.

```dart
/// ```dart
/// var list = [1, 2, 3];
/// ```
/// And then you can also do the following:
/// ```dart continued
/// list.forEach(print);
/// ```
```

--------------------------------

### server.started

Source: https://github.com/dart-lang/sdk/blob/main/pkg/analysis_server/tool/spec/spec_input.html

Notification indicating that the server has started running.

```APIDOC
## NOTIFICATION server.started

### Description
Reports that the server is running. This notification is issued once after the server has started running but before any requests are processed.

### Method
Notification

### Endpoint
server.started

### Parameters
#### Request Body
- **version** (String) - Required - The version number of the analysis server.
- **pid** (int) - Required - The process id of the analysis server process.

### Response
No response is expected for this notification.
```

--------------------------------

### Handle Touch Start Event

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Callback for touch start events. Stores touch positions and focuses elements.

```dart
onTouchStart_(e){this.storeLastTouchPositions_(e);this.focusElements_();}
```

--------------------------------

### Setup Shady DOM

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Initializes the shady DOM properties for a component. This is a setup function and does not directly manipulate the DOM.

```javascript
function(){
this.shadyRoot=null;
if(!this.____domApi){this.____domApi=null;}
if(!this.____dom){this.____dom=null;}
if(!this._ownerShadyRoot){this._ownerShadyRoot=undefined;
}}
```

--------------------------------

### Begin Content Distribution

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Initiates the distribution process by resetting any existing distribution and preparing to distribute nodes from the pool into insertion points.

```javascript
function(){
if(this._useContent&&DomApi.hasInsertionPoint(this.shadyRoot)){
this._resetDistribution();
this._distributePool(this.shadyRoot,this._collectPool());
}}

```

--------------------------------

### Configure Before Clients Ready

Source: https://github.com/dart-lang/sdk/blob/main/pkg/observatory/web/third_party/trace_viewer_full.html

Placeholder method called before component clients are ready. Override for pre-rendering configuration logic.

```javascript
this._beforeClientsReady:function(){this._configure();}
```

--------------------------------

### EntryOptional Instruction

Source: https://github.com/dart-lang/sdk/blob/main/pkg/dart2bytecode/docs/bytecode.md

Function prologue for functions with optional or named arguments. It handles positional and named argument setup, potentially followed by LoadConstant bytecodes for default values.

```bytecode
EntryOptional A, B, C
```