Save metadata to metadata.json (#63)

README.md

@@ -154,8 +154,7 @@ slash.
 Filepack has no way of tracking empty directories, the presence of which are an
 error when creating or verifying a manifest.
 
-Manifests contain an object with one mandatory key, `files`, and one optional
-key, `metadata`.
+Manifests contain an object with one mandatory key, `files`.
 
 ### `files`
 
@@ -182,26 +181,20 @@ An example manifest for a directory containing the files `README.md` and
 }
 ```
 
-### `metadata`
+Metadata
+--------
 
-The value of the optional `metadata` key is an object containing metadata
-describing the package, with keys and values as follows:
+`filepack create` can optionally write metadata describing the contents of the
+package to a file named `metadata.json`, containing a JSON object with the
+following keys:
 
 - `title`: A string containing the package's human-readable title.
 
-An example manifest with metadata:
+An example `metadata.json`:
 
-```json
+```js
 {
-  "files": {
-    "tobins-spirit-guide.md": {
-      "hash": "5a9a6d96244ec398545fc0c98c2cb7ed52511b025c19e9ad1e3c1ef4ac8575ad",
-      "size": 175934
-    }
-  },
-  "metadata": {
-    "title": "Tobin's Spirit Guide"
-  }
+  "title": "Tobin's Spirit Guide"
 }
 ```
 

src/error.rs

@@ -15,6 +15,12 @@ pub(crate) enum Error {
   },
   #[snafu(display("failed to deserialize metadata at `{path}`"))]
   DeserializeMetadata {
+    backtrace: Option<Backtrace>,
+    path: DisplayPath,
+    source: serde_json::Error,
+  },
+  #[snafu(display("failed to deserialize metadata template at `{path}`"))]
+  DeserializeMetadataTemplate {
     backtrace: Option<Backtrace>,
     path: DisplayPath,
     source: serde_yaml::Error,
@@ -59,6 +65,11 @@ pub(crate) enum Error {
     backtrace: Option<Backtrace>,
     path: DisplayPath,
   },
+  #[snafu(display("metadata `{path}` already exists"))]
+  MetadataAlreadyExists {
+    backtrace: Option<Backtrace>,
+    path: DisplayPath,
+  },
   #[snafu(display("manifest hash mismatch"))]
   ManifestHashMismatch { backtrace: Option<Backtrace> },
   #[snafu(display("manifest `{path}` not found"))]

src/io_result_ext.rs

@@ -0,0 +1,39 @@
+use super::*;
+
+pub(crate) trait IoResultExt<T> {
+  fn into_option(self) -> io::Result<Option<T>>;
+}
+
+impl<T> IoResultExt<T> for io::Result<T> {
+  fn into_option(self) -> io::Result<Option<T>> {
+    match self {
+      Err(err) => {
+        if err.kind() == io::ErrorKind::NotFound {
+          Ok(None)
+        } else {
+          Err(err)
+        }
+      }
+      Ok(value) => Ok(Some(value)),
+    }
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  #[test]
+  fn into_option() {
+    Err::<(), io::Error>(io::Error::new(io::ErrorKind::InvalidInput, "foo"))
+      .into_option()
+      .unwrap_err();
+
+    assert_eq!(
+      Err::<(), io::Error>(io::Error::new(io::ErrorKind::NotFound, "foo"))
+        .into_option()
+        .unwrap(),
+      None,
+    );
+  }
+}

src/main.rs

@@ -1,11 +1,11 @@
 use {
   self::{
     arguments::Arguments, display_path::DisplayPath, display_secret::DisplaySecret, entry::Entry,
-    error::Error, hash::Hash, lint::Lint, lint_group::LintGroup, list::List, manifest::Manifest,
-    metadata::Metadata, options::Options, owo_colorize_ext::OwoColorizeExt,
-    private_key::PrivateKey, public_key::PublicKey, relative_path::RelativePath,
-    signature::Signature, signature_error::SignatureError, style::Style, subcommand::Subcommand,
-    template::Template, utf8_path_ext::Utf8PathExt,
+    error::Error, hash::Hash, io_result_ext::IoResultExt, lint::Lint, lint_group::LintGroup,
+    list::List, manifest::Manifest, metadata::Metadata, options::Options,
+    owo_colorize_ext::OwoColorizeExt, private_key::PrivateKey, public_key::PublicKey,
+    relative_path::RelativePath, signature::Signature, signature_error::SignatureError,
+    style::Style, subcommand::Subcommand, template::Template, utf8_path_ext::Utf8PathExt,
   },
   blake3::Hasher,
   camino::{Utf8Component, Utf8Path, Utf8PathBuf},
@@ -40,6 +40,7 @@ mod display_secret;
 mod entry;
 mod error;
 mod hash;
+mod io_result_ext;
 mod lint;
 mod lint_group;
 mod list;

src/manifest.rs

@@ -4,8 +4,6 @@ use super::*;
 #[serde(deny_unknown_fields, rename_all = "kebab-case")]
 pub(crate) struct Manifest {
   pub(crate) files: BTreeMap<RelativePath, Entry>,
-  #[serde(skip_serializing_if = "Option::is_none")]
-  pub(crate) metadata: Option<Metadata>,
 }
 
 impl Manifest {

src/metadata.rs

@@ -6,6 +6,10 @@ pub(crate) struct Metadata {
   title: String,
 }
 
+impl Metadata {
+  pub(crate) const FILENAME: &'static str = "metadata.json";
+}
+
 impl From<Template> for Metadata {
   fn from(Template { title }: Template) -> Self {
     Self { title }

src/subcommand/create.rs

@@ -31,16 +31,19 @@ impl Create {
       root.join(Manifest::FILENAME)
     };
 
-    let metadata = if let Some(path) = &self.metadata {
+    if let Some(path) = &self.metadata {
       let yaml = fs::read_to_string(path).context(error::Io { path })?;
-      Some(
-        serde_yaml::from_str::<Template>(&yaml)
-          .context(error::DeserializeMetadata { path })?
-          .into(),
-      )
-    } else {
-      None
-    };
+      let template = serde_yaml::from_str::<Template>(&yaml)
+        .context(error::DeserializeMetadataTemplate { path })?;
+      let path = root.join(Metadata::FILENAME);
+      ensure! {
+        self.force || !path.try_exists().context(error::Io { path: &path })?,
+        error::MetadataAlreadyExists { path: &path },
+      }
+      let metadata = Metadata::from(template);
+      let json = serde_json::to_string(&metadata).unwrap();
+      fs::write(&path, json).context(error::Io { path: &path })?;
+    }
 
     let cleaned_manifest = current_dir.join(&manifest).lexiclean();
 
@@ -170,7 +173,7 @@ impl Create {
       bar.inc(entry.size);
     }
 
-    let json = serde_json::to_string(&Manifest { files, metadata }).unwrap();
+    let json = serde_json::to_string(&Manifest { files }).unwrap();
 
     fs::write(&manifest, &json).context(error::Io { path: manifest })?;
 

src/subcommand/verify.rs

@@ -196,6 +196,18 @@ mismatched file: `{path}`
       }
     }
 
+    {
+      let path = root.join(Metadata::FILENAME);
+
+      if let Some(json) = fs::read_to_string(&path)
+        .into_option()
+        .context(error::Io { path: &path })?
+      {
+        serde_json::from_str::<Metadata>(&json)
+          .context(error::DeserializeMetadata { path: &path })?;
+      }
+    }
+
     if let Some(key) = self.key {
       ensure! {
         signatures.contains(&key),

tests/create.rs

@@ -462,9 +462,11 @@ fn with_metadata() {
     .success();
 
   dir.child("foo/filepack.json").assert(
-    r#"{"files":{"bar":{"hash":"af1349b9f5f9a1a6a0404dea36dcc9499bcb25c9adc112b7cc9a93cae41f3262","size":0}},"metadata":{"title":"Foo"}}"#,
+    r#"{"files":{"bar":{"hash":"af1349b9f5f9a1a6a0404dea36dcc9499bcb25c9adc112b7cc9a93cae41f3262","size":0},"metadata.json":{"hash":"bf15e6d4fc37be38eb02255ad98c52ac3b54acd1ff7b8de56c343f022eb770de","size":15}}}"#,
   );
 
+  dir.child("foo/metadata.json").assert(r#"{"title":"Foo"}"#);
+
   Command::cargo_bin("filepack")
     .unwrap()
     .args(["verify", "foo"])
@@ -631,3 +633,33 @@ fn existing_signature_will_not_be_overwritten() {
     ))
     .failure();
 }
+
+#[test]
+fn metadata_already_exists() {
+  let dir = TempDir::new().unwrap();
+
+  dir.child("foo/bar").touch().unwrap();
+
+  dir.child("foo/metadata.json").touch().unwrap();
+
+  dir.child("metadata.yaml").write_str("title: Foo").unwrap();
+
+  Command::cargo_bin("filepack")
+    .unwrap()
+    .args(["create", "foo", "--metadata", "metadata.yaml"])
+    .current_dir(&dir)
+    .assert()
+    .stderr(format!(
+      "error: metadata `foo{SEPARATOR}metadata.json` already exists\n"
+    ))
+    .failure();
+
+  Command::cargo_bin("filepack")
+    .unwrap()
+    .args(["create", "foo", "--metadata", "metadata.yaml", "--force"])
+    .current_dir(&dir)
+    .assert()
+    .success();
+
+  dir.child("foo/metadata.json").assert(r#"{"title":"Foo"}"#);
+}

tests/verify.rs

@@ -118,7 +118,7 @@ fn extra_fields_are_not_allowed() {
     .stderr(
       "\
 error: failed to deserialize manifest at `filepack.json`
-       └─ unknown field `foo`, expected `files` or `metadata` at line 1 column 17\n",
+       └─ unknown field `foo`, expected `files` at line 1 column 17\n",
     )
     .failure();
 }
@@ -453,24 +453,6 @@ fn with_manifest_path() {
     .success();
 }
 
-#[test]
-fn manifest_metadata_allows_unknown_keys() {
-  let dir = TempDir::new().unwrap();
-
-  dir.child("foo/bar").touch().unwrap();
-
-  dir.child("foo/filepack.json").write_str(
-    r#"{"files":{"bar":{"hash":"af1349b9f5f9a1a6a0404dea36dcc9499bcb25c9adc112b7cc9a93cae41f3262","size":0}},"metadata":{"title":"Foo","bar":100}}"#,
-  ).unwrap();
-
-  Command::cargo_bin("filepack")
-    .unwrap()
-    .args(["verify", "foo"])
-    .current_dir(&dir)
-    .assert()
-    .success();
-}
-
 #[test]
 fn missing_signature_file_extension() {
   let dir = TempDir::new().unwrap();
@@ -806,3 +788,50 @@ fn ignore_missing() {
     .assert()
     .success();
 }
+
+#[test]
+fn metadata_allows_unknown_keys() {
+  let dir = TempDir::new().unwrap();
+
+  dir
+    .child("filepack.json")
+    .write_str(r#"{"files":{"metadata.json":{"hash":"1845a2ea1b86a250cb1c24115032cc0fdc064001f59af4a5e9a17be5cd7efbbc","size":25}}}"#)
+    .unwrap();
+
+  dir
+    .child("metadata.json")
+    .write_str(r#"{"title":"Foo","bar":100}"#)
+    .unwrap();
+
+  Command::cargo_bin("filepack")
+    .unwrap()
+    .args(["verify"])
+    .current_dir(&dir)
+    .assert()
+    .success();
+}
+
+#[test]
+fn metadata_may_not_be_invalid() {
+  let dir = TempDir::new().unwrap();
+
+  dir
+    .child("filepack.json")
+    .write_str(r#"{"files":{"metadata.json":{"hash":"f113b1430243e68a2976426b0e13f21e5795cc107a914816fbf6c2f511092f4b","size":13}}}"#)
+    .unwrap();
+
+  dir
+    .child("metadata.json")
+    .write_str(r#"{"title":100}"#)
+    .unwrap();
+
+  Command::cargo_bin("filepack")
+    .unwrap()
+    .args(["verify"])
+    .current_dir(&dir)
+    .assert()
+    .stderr(is_match(
+      "error: failed to deserialize metadata at `.*metadata.json`\n.*",
+    ))
+    .failure();
+}