api+json: Create pdu field

resolve #28

Author: KSXGitHub

src/app/sub.rs

@@ -2,7 +2,7 @@ use crate::{
     args::Fraction,
     data_tree::{DataTree, DataTreeReflection},
     fs_tree_builder::FsTreeBuilder,
-    json_data::{JsonData, SchemaVersion, UnitAndTree},
+    json_data::{BinaryVersion, JsonData, SchemaVersion, UnitAndTree},
     os_string_display::OsStringDisplay,
     reporter::ParallelReporter,
     runtime_error::RuntimeError,
@@ -123,6 +123,7 @@ where
                 .into();
             let json_data = JsonData {
                 schema_version: SchemaVersion,
+                binary_version: Some(BinaryVersion::current()),
                 unit_and_tree,
             };
             return serde_json::to_writer(stdout(), &json_data)

src/json_data.rs

@@ -1,5 +1,7 @@
+pub mod binary_version;
 pub mod schema_version;
 
+pub use binary_version::BinaryVersion;
 pub use schema_version::SchemaVersion;
 
 use crate::{
@@ -31,6 +33,9 @@ pub enum UnitAndTree {
 pub struct JsonData {
     /// The `"schema-version"` field.
     pub schema_version: SchemaVersion,
+    /// The `"pdu"` field.
+    #[cfg_attr(feature = "json", serde(rename = "pdu"))]
+    pub binary_version: Option<BinaryVersion>,
     /// The `"unit"` field and the `"tree"` field.
     #[cfg_attr(feature = "json", serde(flatten))]
     pub unit_and_tree: UnitAndTree,

src/json_data/binary_version.rs

@@ -0,0 +1,19 @@
+use derive_more::{AsMut, AsRef, From, FromStr, Into};
+
+#[cfg(feature = "json")]
+use serde::{Deserialize, Serialize};
+
+/// Version of the current `pdu` program.
+pub const CURRENT_VERSION: &str = env!("CARGO_PKG_VERSION");
+
+/// Version of the `pdu` program that created the input JSON.
+#[derive(Debug, Clone, PartialEq, Eq, AsMut, AsRef, From, FromStr, Into)]
+#[cfg_attr(feature = "json", derive(Deserialize, Serialize))]
+pub struct BinaryVersion(String);
+
+impl BinaryVersion {
+    /// Get version of the current `pdu` program as a `BinaryVersion`.
+    pub fn current() -> Self {
+        CURRENT_VERSION.to_string().into()
+    }
+}