fix: make first scenario work

Sponsored-by: author

8 files changed, 89 insertions, 21 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 922b71e..c6da964 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -578,11 +578,13 @@ dependencies = [
 name = "obnam-benchmark"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "fehler",
  "glob",
  "serde",
  "serde_json",
  "serde_yaml",
+ "structopt",
  "subplot-build",
  "subplotlib",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index cfded29..9f1e1ef 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,11 +7,14 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+anyhow = "1.0.51"
 serde = { version = "1.0.101", features = ["derive"] }
 serde_json = "1.0.72"
 serde_yaml = "0.8.21"
+structopt = "0.3.25"
 
 [build-dependencies]
+anyhow = "1.0.51"
 glob = "0.3.0"
 subplot-build = "0.1.0"
 
diff --git a/build.rs b/build.rs
index 0f5c264..1d7729e 100644
--- a/build.rs
+++ b/build.rs
@@ -2,17 +2,25 @@ use glob::glob;
 use std::path::Path;
 
 fn main() {
+    if let Err(err) = real_main() {
+        eprintln!("ERROR: {}", err);
+        std::process::exit(1);
+    }
+}
+
+fn real_main() -> anyhow::Result<()> {
     println!("cargo:rerun-if-env-changed=DEB_BUILD_OPTIONS");
     let subplots = glob("[a-z]*.md").expect("failed to find subplots");
     let tests = Path::new("tests");
     for entry in subplots {
-        let entry = entry.expect("failed to get subplot dir entry");
+        let entry = entry?;
         let mut inc = tests.join(&entry);
         inc.set_extension("rs");
         if !inc.exists() {
             panic!("missing include file: {}", inc.display());
         }
         println!("cargo:rerun-if-changed={}", inc.display());
-        subplot_build::codegen(Path::new(&entry)).expect("failed to generate code with Subplot");
+        subplot_build::codegen(Path::new(&entry))?;
     }
+    Ok(())
 }
diff --git a/obnam-benchmark.md b/obnam-benchmark.md
index cf00fc4..e80ae91 100644
--- a/obnam-benchmark.md
+++ b/obnam-benchmark.md
@@ -39,20 +39,20 @@ how to prepare the test data for each backup generation. Example:
 ```{.yaml .numberLines}
 - benchmark: maildir
   backups:
-  - change:
+  - changes:
     - create:
         files: 100000
         file_size: 0
     - rename:
         files: 1000
-  - change: []
+  - changes: []
 - benchmark: video-footage
   backups:
-  - change:
+  - changes:
     - create:
         files: 1000
         filee_size: 1G
-  - change: []
+  - changes: []
 ```
 
 The example above specifies two benchmarks: "maildir", and
@@ -88,12 +88,11 @@ correctly.
 ```scenario
 given an installed Rust program obnam-benchmark
 given file spec.yaml
-when I run obnam-benchmark dump-spec spec.yaml
-then stdout, as JSON, matches spec.json
-
+given file expected.json
+when I run obnam-benchmark spec.yaml --output spec.json
+then JSON files spec.yaml and expected.json match
 ```
 
-
 ```{#spec.yaml .yaml .file .numberLines}
 benchmarks:
 - benchmark: foo
@@ -101,7 +100,7 @@ benchmarks:
   - changes: []
 ```
 
-```{#spec.json .yaml .file .numberLines}
+```{#expected.json .yaml .file .numberLines}
 {
     "benchmarks": [
         {
diff --git a/src/bin/obnam-benchmark.rs b/src/bin/obnam-benchmark.rs
index 4f2a9ed..617a0a3 100644
--- a/src/bin/obnam-benchmark.rs
+++ b/src/bin/obnam-benchmark.rs
@@ -1,12 +1,35 @@
 use obnam_benchmark::Specification;
+use std::fs::File;
+use std::path::PathBuf;
+use std::process::exit;
+use structopt::StructOpt;
+
+#[derive(Debug, StructOpt)]
+struct Opt {
+    #[structopt(parse(from_os_str))]
+    spec: PathBuf,
+
+    #[structopt(long, parse(from_os_str))]
+    output: PathBuf,
+}
 
 fn main() {
-    let yaml = r#"
-benchmarks:
-- benchmark: foo
-  backups: []
-"#;
-    let spec: Specification = serde_yaml::from_str(yaml).unwrap();
-    serde_json::to_writer(std::io::stdout(), &spec).unwrap();
-    println!();
+    if let Err(err) = real_main() {
+        eprintln!("ERROR: {}", err);
+        exit(1);
+    }
+}
+
+fn real_main() -> anyhow::Result<()> {
+    let opt = Opt::from_args();
+
+    println!("reading {}", opt.spec.display());
+    let input = File::open(&opt.spec)?;
+    let spec: Specification = serde_yaml::from_reader(&input)?;
+
+    println!("writing {}", opt.output.display());
+    let output = File::create(&opt.output)?;
+    serde_json::to_writer(&output, &spec)?;
+
+    Ok(())
 }
diff --git a/subplot/benchmark.rs b/subplot/benchmark.rs
index 1a64ecc..7ea4a94 100644
--- a/subplot/benchmark.rs
+++ b/subplot/benchmark.rs
@@ -1,8 +1,10 @@
 // Implementations of Subplot scenario steps for sshca.md.
 
-use subplotlib::steplibrary::runcmd::Runcmd;
-
+use serde_json::value::Value;
+use std::fs::File;
 use std::path::Path;
+use subplotlib::steplibrary::datadir::Datadir;
+use subplotlib::steplibrary::runcmd::Runcmd;
 
 #[derive(Default)]
 struct SubplotContext {}
@@ -24,3 +26,28 @@ fn install_rust_program(context: &ScenarioContext) {
         false,
     )?;
 }
+
+#[step]
+#[context(Datadir)]
+#[context(SubplotContext)]
+fn json_files_match(context: &ScenarioContext, first: &str, second: &str) {
+    context.with(
+        |context: &Datadir| {
+            let first = context.canonicalise_filename(&first).expect("can't use first filename");
+            let first = File::open(&first)?;
+            let first: Value = serde_json::from_reader(&first)?;
+
+            let second = context.canonicalise_filename(&second).expect("can't use second filename");
+            let second = File::open(&second)?;
+            let second: Value = serde_json::from_reader(&second)?;
+
+            if first != second {
+                eprintln!("JSON files differ:\n{:#?}\n\n{:#?}\n", first, second,);
+                panic!("ERROR: JSON files differ");
+            };
+
+            Ok(())
+        },
+        false,
+    );
+}
diff --git a/subplot/benchmark.yaml b/subplot/benchmark.yaml
index 079abd2..b0e6727 100644
--- a/subplot/benchmark.yaml
+++ b/subplot/benchmark.yaml
@@ -2,3 +2,8 @@
   impl:
     rust:
       function: install_rust_program
+
+- then: JSON files {first} and {second} match
+  impl:
+    rust:
+      function: json_files_match
diff --git a/tests/obnam-benchmark.rs b/tests/obnam-benchmark.rs
new file mode 100644
index 0000000..b6200da
--- /dev/null
+++ b/tests/obnam-benchmark.rs
@@ -0,0 +1 @@
+include!(concat!(env!("OUT_DIR"), "/obnam-benchmark.rs"));