add NIP-07 browser extension signer support for wasm

crates/common/src/web_store.rs

@@ -0,0 +1,32 @@
+use anyhow::{Error, anyhow};
+
+const LOCAL_STORAGE: &str = "localStorage";
+
+fn storage() -> Result<web_sys::Storage, Error> {
+    web_sys::window()
+        .ok_or_else(|| anyhow!("no browser window"))?
+        .local_storage()
+        .map_err(|e| anyhow!("{LOCAL_STORAGE} unavailable: {e:?}"))?
+        .ok_or_else(|| anyhow!("{LOCAL_STORAGE} unavailable"))
+}
+
+/// Read a value previously written with [`set`]
+pub fn get(key: &str) -> Result<Option<String>, Error> {
+    storage()?
+        .get_item(key)
+        .map_err(|e| anyhow!("{LOCAL_STORAGE} read failed: {e:?}"))
+}
+
+/// Write a value, replacing any previous one
+pub fn set(key: &str, value: &str) -> Result<(), Error> {
+    storage()?
+        .set_item(key, value)
+        .map_err(|e| anyhow!("{LOCAL_STORAGE} write failed: {e:?}"))
+}
+
+/// Remove a value if it exists
+pub fn remove(key: &str) -> Result<(), Error> {
+    storage()?
+        .remove_item(key)
+        .map_err(|e| anyhow!("{LOCAL_STORAGE} delete failed: {e:?}"))
+}