From d0ef70e574ec96aba15cb41eb749d542a38012cc Mon Sep 17 00:00:00 2001
From: josh rotenberg <joshrotenberg@gmail.com>
Date: Mon, 26 Apr 2021 08:08:24 -0700
Subject: [PATCH 1/2] use semver to validate version

---
 examples/nop-preprocessor.rs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/examples/nop-preprocessor.rs b/examples/nop-preprocessor.rs
index 90840067..38764207 100644
--- a/examples/nop-preprocessor.rs
+++ b/examples/nop-preprocessor.rs
@@ -3,6 +3,7 @@ use clap::{App, Arg, ArgMatches, SubCommand};
 use mdbook::book::Book;
 use mdbook::errors::Error;
 use mdbook::preprocess::{CmdPreprocessor, Preprocessor, PreprocessorContext};
+use semver::{Version, VersionReq};
 use std::io;
 use std::process;
 
@@ -33,9 +34,10 @@ fn main() {
 fn handle_preprocessing(pre: &dyn Preprocessor) -> Result<(), Error> {
     let (ctx, book) = CmdPreprocessor::parse_input(io::stdin())?;
 
-    if ctx.mdbook_version != mdbook::MDBOOK_VERSION {
-        // We should probably use the `semver` crate to check compatibility
-        // here...
+    let book_version = Version::parse(&ctx.mdbook_version)?;
+    let version_req = VersionReq::parse(mdbook::MDBOOK_VERSION)?;
+
+    if version_req.matches(&book_version) != true {
         eprintln!(
             "Warning: The {} plugin was built against version {} of mdbook, \
              but we're being called from version {}",

From 5b7abf47146f12ea8ac4b4012a6908ee1bf429f4 Mon Sep 17 00:00:00 2001
From: josh rotenberg <joshrotenberg@gmail.com>
Date: Mon, 26 Apr 2021 08:08:53 -0700
Subject: [PATCH 2/2] add semver v0.11.0 for example

---
 Cargo.lock | 21 +++++++++++++++++++++
 Cargo.toml |  1 +
 2 files changed, 22 insertions(+)

diff --git a/Cargo.lock b/Cargo.lock
index d23a2097..e8b510fe 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,5 +1,7 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
 [[package]]
 name = "aho-corasick"
 version = "0.7.10"
@@ -743,6 +745,7 @@ dependencies = [
  "pulldown-cmark",
  "regex",
  "select",
+ "semver",
  "serde",
  "serde_derive",
  "serde_json",
@@ -1204,6 +1207,24 @@ dependencies = [
  "markup5ever_rcdom",
 ]
 
+[[package]]
+name = "semver"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f301af10236f6df4160f7c3f04eec6dbc70ace82d23326abad5edee88801c6b6"
+dependencies = [
+ "semver-parser",
+]
+
+[[package]]
+name = "semver-parser"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "00b0bef5b7f9e0df16536d3961cfb6e84331c065b4066afb39768d0e319411f7"
+dependencies = [
+ "pest",
+]
+
 [[package]]
 name = "serde"
 version = "1.0.106"
diff --git a/Cargo.toml b/Cargo.toml
index 6f5b364c..1824a889 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -49,6 +49,7 @@ ammonia = { version = "3", optional = true }
 
 [dev-dependencies]
 select = "0.5"
+semver = "0.11.0"
 pretty_assertions = "0.6"
 walkdir = "2.0"