Add simple check_contains_version function

This function searches for the a template using a simple substring
match. It is always enabled since it doesn’t need anything outside the
standard library.

.github/workflows/build.yml

@@ -34,12 +34,9 @@ jobs:
 
         # Verify that features work by themselves
         # Features should not interfere with each other
-        # Should only need to check 0, 1, and (all) 3 features enabled
 
-        # Use if statement to invert exit code: this should fail
-      - name: Check failure to build with no features
-        run: if cargo check --no-default-features; then false; else true; fi
-        shell: bash
+      - name: Build and test with no default feature
+        run: cargo test --no-default-features
 
       - name: Build and test with markdown_deps_updated feature
         run: cargo test --no-default-features --features markdown_deps_updated

src/contains_substring.rs

@@ -0,0 +1,67 @@
+use crate::helpers::{read_file, Result};
+
+/// Check that `path` contain the substring given by `template`.
+///
+/// The placeholders `{name}` and `{version}` will be replaced with
+/// `pkg_name` and `pkg_version`, if they are present in `template`.
+/// It is okay if `template` do not contain these placeholders.
+///
+/// See [`check_contains_regex`](crate::check_contains_regex) if you
+/// want to match with a regular expression instead.
+///
+/// # Errors
+///
+/// If the template cannot be found, an `Err` is returned with a
+/// succinct error message. Status information has then already been
+/// printed on `stdout`.
+pub fn check_contains_substring(
+    path: &str,
+    template: &str,
+    pkg_name: &str,
+    pkg_version: &str,
+) -> Result<()> {
+    // Expand the optional {name} and {version} placeholders in the
+    // template. This is almost like
+    //
+    //   format!(template, name = pkg_name, version = pkg_version)
+    //
+    // but allows the user to leave out unnecessary placeholders.
+    let pattern = template
+        .replace("{name}", &pkg_name)
+        .replace("{version}", &pkg_version);
+
+    let text = read_file(path).map_err(|err| format!("could not read {}: {}", path, err))?;
+
+    println!("Searching for \"{}\" in {}...", template, path);
+    match text.find(&pattern) {
+        Some(idx) => {
+            let line_no = text[..idx].lines().count();
+            println!("{} (line {}) ... ok", path, line_no + 1);
+            Ok(())
+        }
+        None => Err(format!("could not find \"{}\" in {}", pattern, path)),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn pattern_not_found() {
+        assert_eq!(
+            check_contains_substring("README.md", "should not be found", "foobar", "1.2.3"),
+            Err(String::from(
+                "could not find \"should not be found\" in README.md"
+            ))
+        )
+    }
+
+    #[test]
+    fn pattern_found() {
+        assert_eq!(
+            check_contains_substring("README.md", "{name}", "version-sync", "1.2.3"),
+            Ok(())
+        )
+    }
+}

src/helpers.rs

@@ -1,4 +1,5 @@
-// Imports are inside the function bodies to scope them in a cfg block.
+use std::fs::File;
+use std::io::{self, Read};
 
 /// The common result type, our errors will be simple strings.
 pub type Result<T> = std::result::Result<T, String>;
@@ -28,10 +29,8 @@ where
 /// Return all data from `path`. Line boundaries are normalized from
 /// "\r\n" to "\n" to make sure "^" and "$" will match them. See
 /// https://github.com/rust-lang/regex/issues/244 for details.
-pub fn read_file(path: &str) -> std::io::Result<String> {
-    use std::io::Read;
-
-    let mut file = std::fs::File::open(path)?;
+pub fn read_file(path: &str) -> io::Result<String> {
+    let mut file = File::open(path)?;
     let mut buf = String::new();
     file.read_to_string(&mut buf)?;
     Ok(buf.replace("\r\n", "\n"))
@@ -45,8 +44,10 @@ pub fn indent(text: &str) -> String {
 
 /// Verify that the version range request matches the given version.
 #[cfg(any(feature = "html_root_url_updated", feature = "markdown_deps_updated"))]
-pub fn version_matches_request(version: &semver_parser::version::Version,
-        request: &semver_parser::range::VersionReq) -> Result<()> {
+pub fn version_matches_request(
+    version: &semver_parser::version::Version,
+    request: &semver_parser::range::VersionReq,
+) -> Result<()> {
     use semver_parser::range::Op;
     if request.predicates.len() != 1 {
         // Can only handle simple dependencies

src/lib.rs

@@ -12,14 +12,15 @@
 //!   dependency on your crate. See [`assert_markdown_deps_updated`].
 //!
 //! * A `Changelog.md` file that should at least mention the current
-//!   version, gated behind the "regex_version" feature.
-//!   See [`assert_contains_regex`].
+//!   version, gated behind the "regex_version" feature. See
+//!   [`assert_contains_regex`] and [`assert_contains_substring`].
 //!
 //! * The [`html_root_url`] attribute that tells other crates where to
 //!   find your documentation, gated behind the "html_root_url" feature.
 //!   See [`assert_html_root_url_updated`].
 //!
-//! The macros are gated behind individual features, as detailed below.
+//! Except for [`assert_contains_substring`], the macros are gated
+//! behind individual features, as detailed below.
 //!
 //! A typical configuration will use an integration test to verify
 //! that all version numbers are in sync. Create a
@@ -29,20 +30,27 @@
 //! #[test]
 //! # fn fake_hidden_test_case_1() {}
 //! # #[cfg(feature = "markdown_deps_updated")]
-//! fn test_readme_deps() {
+//! fn test_readme_deps_updated() {
 //!     version_sync::assert_markdown_deps_updated!("README.md");
 //! }
 //!
 //! #[test]
 //! # fn fake_hidden_test_case_2() {}
+//! fn test_readme_mentions_version() {
+//!     version_sync::assert_contains_substring!("README.md", "Version {version}");
+//! }
+//!
+//! #[test]
+//! # fn fake_hidden_test_case_3() {}
 //! # #[cfg(feature = "html_root_url_updated")]
 //! fn test_html_root_url() {
 //!     version_sync::assert_html_root_url_updated!("src/lib.rs");
 //! }
 //!
 //! # fn main() {
 //! #     #[cfg(feature = "markdown_deps_updated")]
-//! #     test_readme_deps();
+//! #     test_readme_deps_updated();
+//! #     test_readme_mentions_version();
 //! #     #[cfg(feature = "html_root_url_updated")]
 //! #     test_html_root_url();
 //! # }
@@ -53,7 +61,8 @@
 //!
 //! # Cargo Features
 //!
-//! Each of the macros above are gated behind a feature:
+//! In case you only need some of the macros above, you can disable
+//! them individually using Cargo features. The features are:
 //!
 //! * `markdown_deps_updated` enables [`assert_markdown_deps_updated`].
 //! * `html_root_url_updated` enables [`assert_html_root_url_updated`].
@@ -71,17 +80,14 @@
 #![deny(missing_docs)]
 
 mod contains_regex;
+mod contains_substring;
 mod helpers;
 mod html_root_url;
 mod markdown_deps;
 
-// Ensure that at least one feature is enabled
-#[cfg(not(any(feature = "contains_regex", feature = "html_root_url_updated",
-    feature = "markdown_deps_updated")))]
-std::compile_error!("Please select at least one feature.");
-
 #[cfg(feature = "contains_regex")]
 pub use crate::contains_regex::check_contains_regex;
+pub use crate::contains_substring::check_contains_substring;
 #[cfg(feature = "html_root_url_updated")]
 pub use crate::html_root_url::check_html_root_url;
 #[cfg(feature = "markdown_deps_updated")]
@@ -192,12 +198,77 @@ macro_rules! assert_html_root_url_updated {
     };
 }
 
+/// Assert that versions numbers are up to date via substring matching.
+///
+/// This macro allows you verify that the current version number is
+/// mentioned in a particular file, such as a changelog file. You do
+/// this by specifying a template which will be matched against the
+/// content of the file.
+///
+/// The macro calls [`check_contains_substring`] on the file name
+/// given. The package name and current package version is
+/// automatically taken from the `$CARGO_PKG_NAME` and
+/// `$CARGO_PKG_VERSION` environment variables. These environment
+/// variables are automatically set by Cargo when compiling your
+/// crate.
+///
+/// # Usage
+///
+/// The typical way to use this macro is from an integration test:
+///
+/// ```rust
+/// #[test]
+/// # fn fake_hidden_test_case() {}
+/// # // The above function ensures test_readme_mentions_version is
+/// # // compiled.
+/// fn test_readme_mentions_version() {
+///     version_sync::assert_contains_substring!("README.md", "### Version {version}");
+/// }
+///
+/// # fn main() {
+/// #     test_readme_mentions_version();
+/// # }
+/// ```
+///
+/// Tests are run with the current directory set to directory where
+/// your `Cargo.toml` file is, so this will find a `README.md` file
+/// next to your `Cargo.toml` file. It will then check that there is a
+/// heading mentioning the current version of your crate.
+///
+/// The template can contain placeholders which are replaced before
+/// the search begins:
+///
+/// * `{version}`: the current version number of your package.
+/// * `{name}`: the name of your package.
+///
+/// This way you can search for things like `"Latest version of {name}
+/// is: {version}"` and make sure you update your READMEs and
+/// changelogs consistently.
+///
+/// See [`assert_contains_regex`] if you want to search for a regular
+/// expression instead.
+///
+/// # Panics
+///
+/// If the substring cannot be found, `panic!` will be invoked and
+/// your integration test will fail.
+#[macro_export]
+macro_rules! assert_contains_substring {
+    ($path:expr, $format:expr) => {
+        let pkg_name = env!("CARGO_PKG_NAME");
+        let pkg_version = env!("CARGO_PKG_VERSION");
+        if let Err(err) = $crate::check_contains_substring($path, $format, pkg_name, pkg_version) {
+            panic!("{}", err);
+        }
+    };
+}
+
 /// Assert that versions numbers are up to date via a regex.
 ///
 /// This macro allows you verify that the current version number is
 /// mentioned in a particular file, such as a changelog file. You do
 /// this by specifying a regular expression which will be matched
-/// against the file.
+/// against the contents of the file.
 ///
 /// The macro calls [`check_contains_regex`] on the file name given.
 /// The package name and current package version is automatically