refactor: cleanup compiler pipeline (#2686)

* remove fetch_source_file_and_maybe_compile_async and 
  replace it with State.fetch_compiled_module

* remove SourceFile.js_source()

* introduce CompiledModule which is basically the same as
  deno::SourceInfo and represents arbitrary file that has been 
  compiled to JS module

* introduce //cli/compilers module containing all compilers

* introduce JsCompiler which is a no-op compiler
  - output is the same as input, no compilation takes place
  - it is used for MediaType::JavaScript and MediaType::Unknown

* introduce JsonCompiler that wraps JSON in default export

* support JS-to-JS compilation using checkJs

1 files changed, 740 insertions, 0 deletions

diff --git a/cli/compilers/ts.rs b/cli/compilers/ts.rs
new file mode 100644
index 000000000..bbfe33461
--- /dev/null
+++ b/cli/compilers/ts.rs
@@ -0,0 +1,740 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+use crate::compilers::CompiledModule;
+use crate::compilers::CompiledModuleFuture;
+use crate::deno_error::DenoError;
+use crate::diagnostics::Diagnostic;
+use crate::disk_cache::DiskCache;
+use crate::file_fetcher::SourceFile;
+use crate::file_fetcher::SourceFileFetcher;
+use crate::msg;
+use crate::msg::ErrorKind;
+use crate::resources;
+use crate::source_maps::SourceMapGetter;
+use crate::startup_data;
+use crate::state::*;
+use crate::version;
+use crate::worker::Worker;
+use deno::Buf;
+use deno::ErrBox;
+use deno::ModuleSpecifier;
+use futures::Future;
+use futures::Stream;
+use ring;
+use std::collections::HashSet;
+use std::fmt::Write;
+use std::fs;
+use std::path::PathBuf;
+use std::str;
+use std::sync::atomic::Ordering;
+use std::sync::Mutex;
+use url::Url;
+
+/// Struct which represents the state of the compiler
+/// configuration where the first is canonical name for the configuration file,
+/// second is a vector of the bytes of the contents of the configuration file,
+/// third is bytes of the hash of contents.
+#[derive(Clone)]
+pub struct CompilerConfig {
+  pub path: Option<PathBuf>,
+  pub content: Option<Vec<u8>>,
+  pub hash: Vec<u8>,
+}
+
+impl CompilerConfig {
+  /// Take the passed flag and resolve the file name relative to the cwd.
+  pub fn load(config_path: Option<String>) -> Result<Self, ErrBox> {
+    let config_file = match &config_path {
+      Some(config_file_name) => {
+        debug!("Compiler config file: {}", config_file_name);
+        let cwd = std::env::current_dir().unwrap();
+        Some(cwd.join(config_file_name))
+      }
+      _ => None,
+    };
+
+    // Convert the PathBuf to a canonicalized string.  This is needed by the
+    // compiler to properly deal with the configuration.
+    let config_path = match &config_file {
+      Some(config_file) => Some(config_file.canonicalize().unwrap().to_owned()),
+      _ => None,
+    };
+
+    // Load the contents of the configuration file
+    let config = match &config_file {
+      Some(config_file) => {
+        debug!("Attempt to load config: {}", config_file.to_str().unwrap());
+        let config = fs::read(&config_file)?;
+        Some(config)
+      }
+      _ => None,
+    };
+
+    let config_hash = match &config {
+      Some(bytes) => bytes.clone(),
+      _ => b"".to_vec(),
+    };
+
+    let ts_config = Self {
+      path: config_path,
+      content: config,
+      hash: config_hash,
+    };
+
+    Ok(ts_config)
+  }
+
+  pub fn json(self: &Self) -> Result<serde_json::Value, ErrBox> {
+    if self.content.is_none() {
+      return Ok(serde_json::Value::Null);
+    }
+
+    let bytes = self.content.clone().unwrap();
+    let json_string = std::str::from_utf8(&bytes)?;
+    match serde_json::from_str(&json_string) {
+      Ok(json_map) => Ok(json_map),
+      Err(_) => Err(
+        DenoError::new(
+          ErrorKind::InvalidInput,
+          "Compiler config is not a valid JSON".to_string(),
+        ).into(),
+      ),
+    }
+  }
+}
+
+/// Information associated with compiled file in cache.
+/// Includes source code path and state hash.
+/// version_hash is used to validate versions of the file
+/// and could be used to remove stale file in cache.
+pub struct CompiledFileMetadata {
+  pub source_path: PathBuf,
+  pub version_hash: String,
+}
+
+static SOURCE_PATH: &'static str = "source_path";
+static VERSION_HASH: &'static str = "version_hash";
+
+impl CompiledFileMetadata {
+  pub fn from_json_string(metadata_string: String) -> Option<Self> {
+    // TODO: use serde for deserialization
+    let maybe_metadata_json: serde_json::Result<serde_json::Value> =
+      serde_json::from_str(&metadata_string);
+
+    if let Ok(metadata_json) = maybe_metadata_json {
+      let source_path = metadata_json[SOURCE_PATH].as_str().map(PathBuf::from);
+      let version_hash = metadata_json[VERSION_HASH].as_str().map(String::from);
+
+      if source_path.is_none() || version_hash.is_none() {
+        return None;
+      }
+
+      return Some(CompiledFileMetadata {
+        source_path: source_path.unwrap(),
+        version_hash: version_hash.unwrap(),
+      });
+    }
+
+    None
+  }
+
+  pub fn to_json_string(self: &Self) -> Result<String, serde_json::Error> {
+    let mut value_map = serde_json::map::Map::new();
+
+    value_map.insert(SOURCE_PATH.to_owned(), json!(&self.source_path));
+    value_map.insert(VERSION_HASH.to_string(), json!(&self.version_hash));
+    serde_json::to_string(&value_map)
+  }
+}
+/// Creates the JSON message send to compiler.ts's onmessage.
+fn req(
+  root_names: Vec<String>,
+  compiler_config: CompilerConfig,
+  bundle: Option<String>,
+) -> Buf {
+  let j = match (compiler_config.path, compiler_config.content) {
+    (Some(config_path), Some(config_data)) => json!({
+        "rootNames": root_names,
+        "bundle": bundle,
+        "configPath": config_path,
+        "config": str::from_utf8(&config_data).unwrap(),
+      }),
+    _ => json!({
+        "rootNames": root_names,
+        "bundle": bundle,
+      }),
+  };
+
+  j.to_string().into_boxed_str().into_boxed_bytes()
+}
+
+fn gen_hash(v: Vec<&[u8]>) -> String {
+  let mut ctx = ring::digest::Context::new(&ring::digest::SHA1);
+  for src in v.iter() {
+    ctx.update(src);
+  }
+  let digest = ctx.finish();
+  let mut out = String::new();
+  // TODO There must be a better way to do this...
+  for byte in digest.as_ref() {
+    write!(&mut out, "{:02x}", byte).unwrap();
+  }
+  out
+}
+
+/// Emit a SHA1 hash based on source code, deno version and TS config.
+/// Used to check if a recompilation for source code is needed.
+pub fn source_code_version_hash(
+  source_code: &[u8],
+  version: &str,
+  config_hash: &[u8],
+) -> String {
+  gen_hash(vec![source_code, version.as_bytes(), config_hash])
+}
+
+pub struct TsCompiler {
+  pub file_fetcher: SourceFileFetcher,
+  pub config: CompilerConfig,
+  pub disk_cache: DiskCache,
+  /// Set of all URLs that have been compiled. This prevents double
+  /// compilation of module.
+  pub compiled: Mutex<HashSet<Url>>,
+  /// This setting is controlled by `--reload` flag. Unless the flag
+  /// is provided disk cache is used.
+  pub use_disk_cache: bool,
+  /// This setting is controlled by `compilerOptions.checkJs`
+  pub compile_js: bool,
+}
+
+impl TsCompiler {
+  pub fn new(
+    file_fetcher: SourceFileFetcher,
+    disk_cache: DiskCache,
+    use_disk_cache: bool,
+    config_path: Option<String>,
+  ) -> Result<Self, ErrBox> {
+    let config = CompilerConfig::load(config_path)?;
+
+    // If `checkJs` is set to true in `compilerOptions` then we're gonna be compiling
+    // JavaScript files as well
+    let config_json = config.json()?;
+    let compile_js = match &config_json.get("compilerOptions") {
+      Some(serde_json::Value::Object(m)) => match m.get("checkJs") {
+        Some(serde_json::Value::Bool(bool_)) => *bool_,
+        _ => false,
+      },
+      _ => false,
+    };
+
+    let compiler = Self {
+      file_fetcher,
+      disk_cache,
+      config,
+      compiled: Mutex::new(HashSet::new()),
+      use_disk_cache,
+      compile_js,
+    };
+
+    Ok(compiler)
+  }
+
+  /// Create a new V8 worker with snapshot of TS compiler and setup compiler's runtime.
+  fn setup_worker(state: ThreadSafeState) -> Worker {
+    // Count how many times we start the compiler worker.
+    state.metrics.compiler_starts.fetch_add(1, Ordering::SeqCst);
+
+    let mut worker = Worker::new(
+      "TS".to_string(),
+      startup_data::compiler_isolate_init(),
+      // TODO(ry) Maybe we should use a separate state for the compiler.
+      // as was done previously.
+      state.clone(),
+    );
+    worker.execute("denoMain()").unwrap();
+    worker.execute("workerMain()").unwrap();
+    worker.execute("compilerMain()").unwrap();
+    worker
+  }
+
+  pub fn bundle_async(
+    self: &Self,
+    state: ThreadSafeState,
+    module_name: String,
+    out_file: String,
+  ) -> impl Future<Item = (), Error = ErrBox> {
+    debug!(
+      "Invoking the compiler to bundle. module_name: {}",
+      module_name
+    );
+
+    let root_names = vec![module_name.clone()];
+    let req_msg = req(root_names, self.config.clone(), Some(out_file));
+
+    let worker = TsCompiler::setup_worker(state.clone());
+    let resource = worker.state.resource.clone();
+    let compiler_rid = resource.rid;
+    let first_msg_fut =
+      resources::post_message_to_worker(compiler_rid, req_msg)
+        .then(move |_| worker)
+        .then(move |result| {
+          if let Err(err) = result {
+            // TODO(ry) Need to forward the error instead of exiting.
+            eprintln!("{}", err.to_string());
+            std::process::exit(1);
+          }
+          debug!("Sent message to worker");
+          let stream_future =
+            resources::get_message_stream_from_worker(compiler_rid)
+              .into_future();
+          stream_future.map(|(f, _rest)| f).map_err(|(f, _rest)| f)
+        });
+
+    first_msg_fut.map_err(|_| panic!("not handled")).and_then(
+      move |maybe_msg: Option<Buf>| {
+        debug!("Received message from worker");
+
+        if let Some(msg) = maybe_msg {
+          let json_str = std::str::from_utf8(&msg).unwrap();
+          debug!("Message: {}", json_str);
+          if let Some(diagnostics) = Diagnostic::from_emit_result(json_str) {
+            return Err(ErrBox::from(diagnostics));
+          }
+        }
+
+        Ok(())
+      },
+    )
+  }
+
+  /// Mark given module URL as compiled to avoid multiple compilations of same module
+  /// in single run.
+  fn mark_compiled(&self, url: &Url) {
+    let mut c = self.compiled.lock().unwrap();
+    c.insert(url.clone());
+  }
+
+  /// Check if given module URL has already been compiled and can be fetched directly from disk.
+  fn has_compiled(&self, url: &Url) -> bool {
+    let c = self.compiled.lock().unwrap();
+    c.contains(url)
+  }
+
+  /// Asynchronously compile module and all it's dependencies.
+  ///
+  /// This method compiled every module at most once.
+  ///
+  /// If `--reload` flag was provided then compiler will not on-disk cache and force recompilation.
+  ///
+  /// If compilation is required then new V8 worker is spawned with fresh TS compiler.
+  pub fn compile_async(
+    self: &Self,
+    state: ThreadSafeState,
+    source_file: &SourceFile,
+  ) -> Box<CompiledModuleFuture> {
+    if self.has_compiled(&source_file.url) {
+      return match self.get_compiled_module(&source_file.url) {
+        Ok(compiled) => Box::new(futures::future::ok(compiled)),
+        Err(err) => Box::new(futures::future::err(err)),
+      };
+    }
+
+    if self.use_disk_cache {
+      // Try to load cached version:
+      // 1. check if there's 'meta' file
+      if let Some(metadata) = self.get_metadata(&source_file.url) {
+        // 2. compare version hashes
+        // TODO: it would probably be good idea to make it method implemented on SourceFile
+        let version_hash_to_validate = source_code_version_hash(
+          &source_file.source_code,
+          version::DENO,
+          &self.config.hash,
+        );
+
+        if metadata.version_hash == version_hash_to_validate {
+          debug!("load_cache metadata version hash match");
+          if let Ok(compiled_module) =
+            self.get_compiled_module(&source_file.url)
+          {
+            self.mark_compiled(&source_file.url);
+            return Box::new(futures::future::ok(compiled_module));
+          }
+        }
+      }
+    }
+
+    let source_file_ = source_file.clone();
+
+    debug!(">>>>> compile_sync START");
+    let module_url = source_file.url.clone();
+
+    debug!(
+      "Running rust part of compile_sync, module specifier: {}",
+      &source_file.url
+    );
+
+    let root_names = vec![module_url.to_string()];
+    let req_msg = req(root_names, self.config.clone(), None);
+
+    let worker = TsCompiler::setup_worker(state.clone());
+    let compiling_job = state.progress.add("Compile", &module_url.to_string());
+    let state_ = state.clone();
+
+    let resource = worker.state.resource.clone();
+    let compiler_rid = resource.rid;
+    let first_msg_fut =
+      resources::post_message_to_worker(compiler_rid, req_msg)
+        .then(move |_| worker)
+        .then(move |result| {
+          if let Err(err) = result {
+            // TODO(ry) Need to forward the error instead of exiting.
+            eprintln!("{}", err.to_string());
+            std::process::exit(1);
+          }
+          debug!("Sent message to worker");
+          let stream_future =
+            resources::get_message_stream_from_worker(compiler_rid)
+              .into_future();
+          stream_future.map(|(f, _rest)| f).map_err(|(f, _rest)| f)
+        });
+
+    let fut = first_msg_fut
+      .map_err(|_| panic!("not handled"))
+      .and_then(move |maybe_msg: Option<Buf>| {
+        debug!("Received message from worker");
+
+        if let Some(msg) = maybe_msg {
+          let json_str = std::str::from_utf8(&msg).unwrap();
+          debug!("Message: {}", json_str);
+          if let Some(diagnostics) = Diagnostic::from_emit_result(json_str) {
+            return Err(ErrBox::from(diagnostics));
+          }
+        }
+
+        Ok(())
+      }).and_then(move |_| {
+        // if we are this far it means compilation was successful and we can
+        // load compiled filed from disk
+        state_
+          .ts_compiler
+          .get_compiled_module(&source_file_.url)
+          .map_err(|e| {
+            // TODO: this situation shouldn't happen
+            panic!("Expected to find compiled file: {}", e)
+          })
+      }).and_then(move |compiled_module| {
+        // Explicit drop to keep reference alive until future completes.
+        drop(compiling_job);
+
+        Ok(compiled_module)
+      }).then(move |r| {
+        debug!(">>>>> compile_sync END");
+        // TODO(ry) do this in worker's destructor.
+        // resource.close();
+        r
+      });
+
+    Box::new(fut)
+  }
+
+  /// Get associated `CompiledFileMetadata` for given module if it exists.
+  pub fn get_metadata(self: &Self, url: &Url) -> Option<CompiledFileMetadata> {
+    // Try to load cached version:
+    // 1. check if there's 'meta' file
+    let cache_key = self
+      .disk_cache
+      .get_cache_filename_with_extension(url, "meta");
+    if let Ok(metadata_bytes) = self.disk_cache.get(&cache_key) {
+      if let Ok(metadata) = std::str::from_utf8(&metadata_bytes) {
+        if let Some(read_metadata) =
+          CompiledFileMetadata::from_json_string(metadata.to_string())
+        {
+          return Some(read_metadata);
+        }
+      }
+    }
+
+    None
+  }
+
+  pub fn get_compiled_module(
+    self: &Self,
+    module_url: &Url,
+  ) -> Result<CompiledModule, ErrBox> {
+    let compiled_source_file = self.get_compiled_source_file(module_url)?;
+
+    let compiled_module = CompiledModule {
+      code: str::from_utf8(&compiled_source_file.source_code)
+        .unwrap()
+        .to_string(),
+      name: module_url.to_string(),
+    };
+
+    Ok(compiled_module)
+  }
+
+  /// Return compiled JS file for given TS module.
+  // TODO: ideally we shouldn't construct SourceFile by hand, but it should be delegated to
+  // SourceFileFetcher
+  pub fn get_compiled_source_file(
+    self: &Self,
+    module_url: &Url,
+  ) -> Result<SourceFile, ErrBox> {
+    let cache_key = self
+      .disk_cache
+      .get_cache_filename_with_extension(&module_url, "js");
+    let compiled_code = self.disk_cache.get(&cache_key)?;
+    let compiled_code_filename = self.disk_cache.location.join(cache_key);
+    debug!("compiled filename: {:?}", compiled_code_filename);
+
+    let compiled_module = SourceFile {
+      url: module_url.clone(),
+      filename: compiled_code_filename,
+      media_type: msg::MediaType::JavaScript,
+      source_code: compiled_code,
+    };
+
+    Ok(compiled_module)
+  }
+
+  /// Save compiled JS file for given TS module to on-disk cache.
+  ///
+  /// Along compiled file a special metadata file is saved as well containing
+  /// hash that can be validated to avoid unnecessary recompilation.
+  fn cache_compiled_file(
+    self: &Self,
+    module_specifier: &ModuleSpecifier,
+    contents: &str,
+  ) -> std::io::Result<()> {
+    let js_key = self
+      .disk_cache
+      .get_cache_filename_with_extension(module_specifier.as_url(), "js");
+    self
+      .disk_cache
+      .set(&js_key, contents.as_bytes())
+      .and_then(|_| {
+        self.mark_compiled(module_specifier.as_url());
+
+        let source_file = self
+          .file_fetcher
+          .fetch_source_file(&module_specifier)
+          .expect("Source file not found");
+
+        let version_hash = source_code_version_hash(
+          &source_file.source_code,
+          version::DENO,
+          &self.config.hash,
+        );
+
+        let compiled_file_metadata = CompiledFileMetadata {
+          source_path: source_file.filename.to_owned(),
+          version_hash,
+        };
+        let meta_key = self
+          .disk_cache
+          .get_cache_filename_with_extension(module_specifier.as_url(), "meta");
+        self.disk_cache.set(
+          &meta_key,
+          compiled_file_metadata.to_json_string()?.as_bytes(),
+        )
+      })
+  }
+
+  /// Return associated source map file for given TS module.
+  // TODO: ideally we shouldn't construct SourceFile by hand, but it should be delegated to
+  // SourceFileFetcher
+  pub fn get_source_map_file(
+    self: &Self,
+    module_specifier: &ModuleSpecifier,
+  ) -> Result<SourceFile, ErrBox> {
+    let cache_key = self
+      .disk_cache
+      .get_cache_filename_with_extension(module_specifier.as_url(), "js.map");
+    let source_code = self.disk_cache.get(&cache_key)?;
+    let source_map_filename = self.disk_cache.location.join(cache_key);
+    debug!("source map filename: {:?}", source_map_filename);
+
+    let source_map_file = SourceFile {
+      url: module_specifier.as_url().to_owned(),
+      filename: source_map_filename,
+      media_type: msg::MediaType::JavaScript,
+      source_code,
+    };
+
+    Ok(source_map_file)
+  }
+
+  /// Save source map file for given TS module to on-disk cache.
+  fn cache_source_map(
+    self: &Self,
+    module_specifier: &ModuleSpecifier,
+    contents: &str,
+  ) -> std::io::Result<()> {
+    let source_map_key = self
+      .disk_cache
+      .get_cache_filename_with_extension(module_specifier.as_url(), "js.map");
+    self.disk_cache.set(&source_map_key, contents.as_bytes())
+  }
+
+  /// This method is called by TS compiler via an "op".
+  pub fn cache_compiler_output(
+    self: &Self,
+    module_specifier: &ModuleSpecifier,
+    extension: &str,
+    contents: &str,
+  ) -> std::io::Result<()> {
+    match extension {
+      ".map" => self.cache_source_map(module_specifier, contents),
+      ".js" => self.cache_compiled_file(module_specifier, contents),
+      _ => unreachable!(),
+    }
+  }
+}
+
+impl SourceMapGetter for TsCompiler {
+  fn get_source_map(&self, script_name: &str) -> Option<Vec<u8>> {
+    self
+      .try_to_resolve_and_get_source_map(script_name)
+      .and_then(|out| Some(out.source_code))
+  }
+
+  fn get_source_line(&self, script_name: &str, line: usize) -> Option<String> {
+    self
+      .try_resolve_and_get_source_file(script_name)
+      .and_then(|out| {
+        str::from_utf8(&out.source_code).ok().and_then(|v| {
+          let lines: Vec<&str> = v.lines().collect();
+          assert!(lines.len() > line);
+          Some(lines[line].to_string())
+        })
+      })
+  }
+}
+
+// `SourceMapGetter` related methods
+impl TsCompiler {
+  fn try_to_resolve(self: &Self, script_name: &str) -> Option<ModuleSpecifier> {
+    // if `script_name` can't be resolved to ModuleSpecifier it's probably internal
+    // script (like `gen/cli/bundle/compiler.js`) so we won't be
+    // able to get source for it anyway
+    ModuleSpecifier::resolve_url(script_name).ok()
+  }
+
+  fn try_resolve_and_get_source_file(
+    &self,
+    script_name: &str,
+  ) -> Option<SourceFile> {
+    if let Some(module_specifier) = self.try_to_resolve(script_name) {
+      return match self.file_fetcher.fetch_source_file(&module_specifier) {
+        Ok(out) => Some(out),
+        Err(_) => None,
+      };
+    }
+
+    None
+  }
+
+  fn try_to_resolve_and_get_source_map(
+    &self,
+    script_name: &str,
+  ) -> Option<SourceFile> {
+    if let Some(module_specifier) = self.try_to_resolve(script_name) {
+      return match self.get_source_map_file(&module_specifier) {
+        Ok(out) => Some(out),
+        Err(_) => None,
+      };
+    }
+
+    None
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+  use crate::tokio_util;
+  use deno::ModuleSpecifier;
+  use std::path::PathBuf;
+
+  impl TsCompiler {
+    fn compile_sync(
+      self: &Self,
+      state: ThreadSafeState,
+      source_file: &SourceFile,
+    ) -> Result<CompiledModule, ErrBox> {
+      tokio_util::block_on(self.compile_async(state, source_file))
+    }
+  }
+
+  #[test]
+  fn test_compile_sync() {
+    tokio_util::init(|| {
+      let specifier =
+        ModuleSpecifier::resolve_url_or_path("./tests/002_hello.ts").unwrap();
+
+      let out = SourceFile {
+        url: specifier.as_url().clone(),
+        filename: PathBuf::from("/tests/002_hello.ts"),
+        media_type: msg::MediaType::TypeScript,
+        source_code: include_bytes!("../../tests/002_hello.ts").to_vec(),
+      };
+
+      let mock_state = ThreadSafeState::mock(vec![
+        String::from("./deno"),
+        String::from("hello.js"),
+      ]);
+      let compiled = mock_state
+        .ts_compiler
+        .compile_sync(mock_state.clone(), &out)
+        .unwrap();
+      assert!(
+        compiled
+          .code
+          .as_bytes()
+          .starts_with("console.log(\"Hello World\");".as_bytes())
+      );
+    })
+  }
+
+  #[test]
+  fn test_bundle_async() {
+    let specifier = "./tests/002_hello.ts";
+    use deno::ModuleSpecifier;
+    let module_name = ModuleSpecifier::resolve_url_or_path(specifier)
+      .unwrap()
+      .to_string();
+
+    let state = ThreadSafeState::mock(vec![
+      String::from("./deno"),
+      String::from("./tests/002_hello.ts"),
+      String::from("$deno$/bundle.js"),
+    ]);
+    let out = state.ts_compiler.bundle_async(
+      state.clone(),
+      module_name,
+      String::from("$deno$/bundle.js"),
+    );
+    assert!(tokio_util::block_on(out).is_ok());
+  }
+
+  #[test]
+  fn test_source_code_version_hash() {
+    assert_eq!(
+      "08574f9cdeb94fd3fb9cdc7a20d086daeeb42bca",
+      source_code_version_hash(b"1+2", "0.4.0", b"{}")
+    );
+    // Different source_code should result in different hash.
+    assert_eq!(
+      "d8abe2ead44c3ff8650a2855bf1b18e559addd06",
+      source_code_version_hash(b"1", "0.4.0", b"{}")
+    );
+    // Different version should result in different hash.
+    assert_eq!(
+      "d6feffc5024d765d22c94977b4fe5975b59d6367",
+      source_code_version_hash(b"1", "0.1.0", b"{}")
+    );
+    // Different config should result in different hash.
+    assert_eq!(
+      "3b35db249b26a27decd68686f073a58266b2aec2",
+      source_code_version_hash(b"1", "0.4.0", b"{\"compilerOptions\": {}}")
+    );
+  }
+}