[wasm-metadata] Split lib.rs into separate files (#1917)

* split tests into their own file

* move producers

* move component_names

* move module_names

* continue splitting tests

* group names in a subdir

* group names in subdir

* move metadata to its own file

* refactor remaining parts

* add doc comment

* inline module tests into their respective modules

crates/wasm-metadata/src/add_metadata.rs

@@ -0,0 +1,61 @@
+use crate::{rewrite_wasm, Producers, RegistryMetadata};
+
+use anyhow::Result;
+
+/// Add metadata (module name, producers) to a WebAssembly file.
+///
+/// Supports both core WebAssembly modules and components. In components,
+/// metadata will be added to the outermost component.
+#[cfg_attr(feature = "clap", derive(clap::Parser))]
+#[derive(Debug, Clone, Default)]
+pub struct AddMetadata {
+    /// Add a module or component name to the names section
+    #[cfg_attr(feature = "clap", clap(long, value_name = "NAME"))]
+    pub name: Option<String>,
+
+    /// Add a programming language to the producers section
+    #[cfg_attr(feature = "clap", clap(long, value_name = "NAME"))]
+    pub language: Vec<String>,
+
+    /// Add a tool and its version to the producers section
+    #[cfg_attr(feature = "clap", clap(long = "processed-by", value_parser = parse_key_value, value_name="NAME=VERSION"))]
+    pub processed_by: Vec<(String, String)>,
+
+    /// Add an SDK and its version to the producers section
+    #[cfg_attr(feature="clap", clap(long, value_parser = parse_key_value, value_name="NAME=VERSION"))]
+    pub sdk: Vec<(String, String)>,
+
+    /// Add an registry metadata to the registry-metadata section
+    #[cfg_attr(feature="clap", clap(long, value_parser = parse_registry_metadata_value, value_name="PATH"))]
+    pub registry_metadata: Option<RegistryMetadata>,
+}
+
+#[cfg(feature = "clap")]
+pub(crate) fn parse_key_value(s: &str) -> Result<(String, String)> {
+    s.split_once('=')
+        .map(|(k, v)| (k.to_owned(), v.to_owned()))
+        .ok_or_else(|| anyhow::anyhow!("expected KEY=VALUE"))
+}
+
+#[cfg(feature = "clap")]
+pub(crate) fn parse_registry_metadata_value(s: &str) -> Result<RegistryMetadata> {
+    let contents = std::fs::read(s)?;
+
+    let registry_metadata = RegistryMetadata::from_bytes(&contents, 0)?;
+
+    Ok(registry_metadata)
+}
+
+impl AddMetadata {
+    /// Process a WebAssembly binary. Supports both core WebAssembly modules, and WebAssembly
+    /// components. The module and component will have, at very least, an empty name and producers
+    /// section created.
+    pub fn to_wasm(&self, input: &[u8]) -> Result<Vec<u8>> {
+        rewrite_wasm(
+            &self.name,
+            &Producers::from_meta(self),
+            self.registry_metadata.as_ref(),
+            input,
+        )
+    }
+}