feat(iroh-net-report): Support wasm32 building & running (#3139)

## Description

This makes iroh-net-report compile to Wasm. We make sure it's likely to
work by grepping the generated Wasm file for "env" imports (which would
make it not work in browsers).
Mostly this will disable functionality in iroh-net-report for the
browser target - specifically, it disables STUN, QAD, ICMP and all other
probes besides HTTPS to relays.
I've experimentally verified this code works with an integration test,
it's really hard to come up with a good strategy for automating this
testing due to requiring running cross-languages.
I'd like to do that as a follow-up once #3145 is merged.

## Change checklist

- [x] Self-review.
- [x] Documentation updates following the [style
guide](https://rust-lang.github.io/rfcs/1574-more-api-documentation-conventions.html#appendix-a-full-conventions-text),
if relevant.

.github/workflows/ci.yml

@@ -169,11 +169,20 @@ jobs:
       - name: wasm32 build (iroh-relay)
         run: cargo build --target wasm32-unknown-unknown -p iroh-relay --no-default-features
 
+      - name: wasm32 build (iroh-net-report)
+        run: cargo build --target wasm32-unknown-unknown -p iroh-net-report --no-default-features
+
       # If the Wasm file contains any 'import "env"' declarations, then
       # some non-Wasm-compatible code made it into the final code.
       - name: Ensure no 'import "env"' in iroh-relay Wasm
         run: |
           ! wasm-tools print --skeleton target/wasm32-unknown-unknown/debug/iroh_relay.wasm | grep 'import "env"'
+
+      # If the Wasm file contains any 'import "env"' declarations, then
+      # some non-Wasm-compatible code made it into the final code.
+      - name: Ensure no 'import "env"' in iroh-net-report Wasm
+        run: |
+          ! wasm-tools print --skeleton target/wasm32-unknown-unknown/debug/iroh_net_report.wasm | grep 'import "env"'
       
 
   check_semver:

iroh-net-report/Cargo.toml

@@ -12,38 +12,49 @@ keywords = ["networking"]
 # Sadly this also needs to be updated in .github/workflows/ci.yml
 rust-version = "1.81"
 
+[lib]
+crate-type = ["lib", "cdylib"] # cdylib is needed for Wasm support
+
 [lints]
 workspace = true
 
 [dependencies]
 anyhow = "1"
 bytes = "1.7"
 derive_more = { version = "1.0.0", features = ["display"] }
-hickory-resolver = "=0.25.0-alpha.5"
 iroh-base = { version = "0.32.0", path = "../iroh-base", default-features = false, features = ["relay"] }
 iroh-metrics = { version = "0.31", default-features = false }
-iroh-relay = { version = "0.32", path = "../iroh-relay" }
+iroh-relay = { version = "0.32", default-features = false, path = "../iroh-relay" }
 n0-future = "0.1.2"
-netwatch = { version = "0.3" }
-portmapper = { version = "0.3", default-features = false }
-quinn = { package = "iroh-quinn", version = "0.13.0" }
+quinn = { package = "iroh-quinn", version = "0.13.0", default-features = false }
 rand = "0.8"
-reqwest = { version = "0.12", default-features = false }
+reqwest = { version = "0.12", default-features = false, features = ["stream"] }
 rustls = { version = "0.23", default-features = false }
-surge-ping = "0.8.0"
 thiserror = "2"
 tokio = { version = "1", default-features = false, features = ["sync", "time", "macros", "rt"] }
 tokio-util = { version = "0.7.12", default-features = false }
 tracing = "0.1"
 url = { version = "2.4" }
 
+# non-wasm-in-browser dependencies
+[target.'cfg(not(all(target_family = "wasm", target_os = "unknown")))'.dependencies]
+hickory-resolver = "=0.25.0-alpha.5"
+netwatch = { version = "0.3" }
+portmapper = { version = "0.3", default-features = false }
+surge-ping = "0.8.0"
+
 [dev-dependencies]
+futures-lite = "2.3"
 iroh-relay = { path = "../iroh-relay", features = ["test-utils", "server"] }
 pretty_assertions = "1.4"
+quinn = { package = "iroh-quinn", version = "0.13.0" }
 testresult = "0.4.0"
 tokio = { version = "1", default-features = false, features = ["test-util"] }
 tracing-test = "0.2.5"
 
+[build-dependencies]
+cfg_aliases = { version = "0.2" }
+
 [features]
 default = ["metrics"]
 metrics = ["iroh-metrics/metrics", "portmapper/metrics"]

iroh-net-report/build.rs

@@ -0,0 +1,9 @@
+use cfg_aliases::cfg_aliases;
+
+fn main() {
+    // Setup cfg aliases
+    cfg_aliases! {
+        // Convenience aliases
+        wasm_browser: { all(target_family = "wasm", target_os = "unknown") },
+    }
+}