Flag to hide extension details (#293)

That way understanding which extension is present is a bit easier

gitoxide-core/src/index/information.rs

@@ -1,5 +1,10 @@
 use git_repository as git;
-use std::convert::TryFrom;
+
+pub struct Options {
+    pub index: super::Options,
+    /// If true, show exstension in detail.
+    pub extension_details: bool,
+}
 
 mod ext {
     #[cfg_attr(feature = "serde1", derive(serde::Serialize))]
@@ -76,18 +81,16 @@ pub(crate) struct Collection {
     extensions: Extensions,
 }
 
-impl TryFrom<git::index::File> for Collection {
-    type Error = anyhow::Error;
-
-    fn try_from(f: git::index::File) -> Result<Self, Self::Error> {
+impl Collection {
+    pub fn try_from_file(f: git::index::File, extension_details: bool) -> anyhow::Result<Self> {
         Ok(Collection {
             version: f.version() as u8,
             checksum: f.checksum.to_hex().to_string(),
             extensions: {
                 let mut count = 0;
-                let tree = f.tree().map(|tree| {
+                let tree = f.tree().and_then(|tree| {
                     count += 1;
-                    tree.into()
+                    extension_details.then(|| tree.into())
                 });
                 if f.link().is_some() {
                     count += 1

gitoxide-core/src/index/mod.rs

@@ -10,13 +10,16 @@ pub struct Options {
 mod entries;
 
 #[cfg(feature = "serde1")]
-mod information;
+pub mod information;
 
 #[cfg_attr(not(feature = "serde1"), allow(unused_variables))]
 pub fn information(
     index_path: impl AsRef<Path>,
     out: impl std::io::Write,
-    Options { object_hash, format }: Options,
+    information::Options {
+        index: Options { object_hash, format },
+        extension_details,
+    }: information::Options,
 ) -> anyhow::Result<()> {
     use crate::OutputFormat::*;
     match format {
@@ -25,8 +28,7 @@ pub fn information(
         }
         #[cfg(feature = "serde1")]
         Json => {
-            use std::convert::TryFrom;
-            let info = information::Collection::try_from(parse_file(index_path, object_hash)?)?;
+            let info = information::Collection::try_from_file(parse_file(index_path, object_hash)?, extension_details)?;
             serde_json::to_writer_pretty(out, &info)?;
             Ok(())
         }

src/plumbing/main.rs

@@ -78,14 +78,21 @@ pub fn main() -> Result<()> {
             index_path,
             cmd,
         }) => match cmd {
-            index::Subcommands::Info => prepare_and_run(
+            index::Subcommands::Info { no_details } => prepare_and_run(
                 "index-entries",
                 verbose,
                 progress,
                 progress_keep_open,
                 None,
                 move |_progress, out, _err| {
-                    core::index::information(index_path, out, core::index::Options { object_hash, format })
+                    core::index::information(
+                        index_path,
+                        out,
+                        core::index::information::Options {
+                            index: core::index::Options { object_hash, format },
+                            extension_details: !no_details,
+                        },
+                    )
                 },
             ),
             index::Subcommands::Entries => prepare_and_run(

src/plumbing/options.rs

@@ -356,7 +356,11 @@ pub mod index {
         /// Print all entries to standard output
         Entries,
         /// Print information about the index structure
-        Info,
+        Info {
+            /// Do not extract specific extension information to gain only a superficial idea of the index's composition.
+            #[clap(long)]
+            no_details: bool,
+        },
     }
 }