Implement the load_from_file function

The implementation is dead simple, and pretty dumb. I'm not going to
figure out all the different IO errors I might see. Instead, the
function will report that it couldn't read the file and call it good.

.gitea/workflows/release.yml

@@ -8,6 +8,11 @@ jobs:
     name: Compile and upload a release build
     steps:
       - uses: actions/checkout@v4
+      - name: Get Cargo version
+        run: echo "cargo_version=v$(grep "^version" Cargo.toml | cut -d \" -f2)" >> $GITHUB_ENV
+      - name: Abort if Cargo.toml & Git Tag versions don't match
+        if: ${{ env.cargo_version != github.ref_name }}
+        run: exit 1
       - name: Install Rust Stable
         uses: dtolnay/rust-toolchain@stable
       - name: Build binary crate

Cargo.toml

@@ -10,6 +10,7 @@ itertools = "0.10.0"
 reqwest = { version = "0.11.13", features = ["json", "stream", "multipart"] }
 serde = { version = "1.0.152", features = ["derive"] }
 tokio = { version = "1.24.2", features = ["macros", "rt-multi-thread"] }
+toml = "0.5"
 
 # Packages available in Debian (Sid)
 # clap = "4.5.23"

README.md

@@ -1,4 +1,4 @@
-# gt-tools
+# gt-tool
 
 CLI tools for interacting with the Gitea API. Use interactively to talk to your Gitea instance, or automatically via a CI/CD pipeline.
 

src/config.rs

@@ -0,0 +1,283 @@
+use toml::{Value, value::Table};
+
+pub type Result<T> = core::result::Result<T, Error>;
+
+#[derive(Debug)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum Error {
+    BadFormat,
+    NoSuchProperty,
+    NoSuchTable,
+    CouldntReadFile,
+    TomlWrap(toml::de::Error),
+}
+
+impl From<toml::de::Error> for Error {
+    fn from(value: toml::de::Error) -> Self {
+        Error::TomlWrap(value)
+    }
+}
+
+impl core::fmt::Display for Error{
+	fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		// FIXME: Print a nice output, don't just reuse the Debug impl
+		write!(fmt, "{self:?}")
+	}
+}
+
+impl std::error::Error for Error {}
+
+#[derive(Debug, Default)]
+#[cfg_attr(test, derive(PartialEq))]
+struct PartialConfig {
+    project_path: Option<String>,
+    gitea_url: Option<String>,
+    owner: Option<String>,
+    repo: Option<String>,
+    token: Option<String>,
+}
+
+impl PartialConfig {
+    // One lonely builder-pattern function to set the project path.
+    // This is so I can do continuation style calls instead of a bunch of
+    // successive `let conf = ...` temporaries.
+    fn project_path(self, path: impl ToString) -> Self{
+        PartialConfig {
+            project_path: Some(path.to_string()),
+            ..self
+        }
+    }
+}
+
+impl TryFrom<&Table> for PartialConfig {
+    type Error = crate::config::Error;
+
+    fn try_from(value: &Table) -> Result<Self> {
+        Ok(Self {
+            // can't get table name because that key is gone by this point.
+            project_path: None,
+            gitea_url: get_maybe_property(&value, "gitea_url")?.cloned(),
+            owner: get_maybe_property(&value, "owner")?.cloned(),
+            repo: get_maybe_property(&value, "repo")?.cloned(),
+            token: get_maybe_property(&value, "token")?.cloned(),
+        })
+    }
+
+}
+
+#[derive(Debug, Default)]
+#[cfg_attr(test, derive(PartialEq))]
+struct WholeFile {
+    all: PartialConfig,
+    project_overrides: Vec<PartialConfig>,
+}
+
+fn load_from_file(path: &str) -> Result<WholeFile> {
+    let res = std::fs::read_to_string(path);
+    match res {
+        Ok(s) => read_conf_str(s.as_str()),
+        Err(e) => {
+            eprintln!("->> file io err: {:?}", e);
+            Err(Error::CouldntReadFile)
+        }
+    }
+}
+
+fn read_conf_str(text: &str) -> Result<WholeFile> {
+    let mut whole = WholeFile::default();
+
+    let toml_val = text.parse::<Value>()?;
+
+    // The config file is one big table. If the string we decoded is
+    // some other toml::Value variant, it's not correct.
+    // Try getting it as a table, return Err(BadFormat) otherwise.
+    let cfg_table = toml_val.as_table().ok_or(Error::BadFormat)?;
+
+    // Get the global config out of the file
+    let table_all = get_table(cfg_table, "all")?;
+    whole.all = PartialConfig::try_from(table_all)?;
+
+    // Loop over the per-project configs, if any.
+    let per_project_keys = cfg_table
+        .keys()
+        .filter(|s| { // Discard the "[all]" table
+            *s != "all"
+        });
+
+    for path in per_project_keys {
+        let tab = get_table(cfg_table, path)?;
+        let part_cfg = PartialConfig::try_from(tab)?
+            .project_path(path.clone());
+        whole.project_overrides.push(part_cfg);
+    }
+    Ok(whole)
+}
+
+/// The outer value must be a Table so we can get the sub-table from it.
+fn get_table<'outer>(outer: &'outer Table, table_name: impl ToString) -> Result<&'outer Table> {
+    Ok(outer
+        .get(&table_name.to_string())
+        .ok_or(Error::NoSuchTable)?
+        .as_table()
+        .ok_or(Error::BadFormat)?)
+}
+
+
+/// Similar to `get_property()` but maps the "Error::NoSuchProperty" result to
+/// Option::None. Some properties aren't specified, and that's okay... sometimes.
+fn get_maybe_property<'outer> (outer: &'outer Table, property: impl ToString) -> Result<Option<&'outer String>> {
+    let maybe_prop = get_property(outer, property);
+    match maybe_prop {
+        Ok(value) => Ok(Some(value)),
+        Err(e) => {
+            if let Error::NoSuchProperty = e {
+                return Ok(None);
+            } else {
+                return Err(e);
+            }
+        }
+    }
+}
+
+/// The config properties are individual strings. This gets the named property,
+/// or an error explaining why it couldn't be fetched.
+fn get_property<'outer>(outer: &'outer Table, property: impl ToString) -> Result<&'outer String> {
+    let maybe_prop = outer.get(&property.to_string()).ok_or(Error::NoSuchProperty)?;
+    if let Value::String(text) = maybe_prop {
+        Ok(text)
+    } else {
+        Err(Error::BadFormat)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use toml::map::Map;
+
+    use super::*;
+
+    // Util for generating a reference struct
+    fn gen_expected_struct() -> WholeFile {
+        WholeFile {
+            all: PartialConfig {
+                project_path: None,
+                gitea_url: Some(String::from("http://localhost:3000")),
+                owner: None,
+                repo: None,
+                token: Some(String::from("fake-token"))
+            },
+            project_overrides: vec![
+                PartialConfig {
+                    project_path: Some(String::from("/home/robert/projects/gt-tool")),
+                    gitea_url: None,
+                    owner: Some(String::from("robert")),
+                    repo: Some(String::from("gt-tool")),
+                    token: None,
+                },
+                PartialConfig {
+                    project_path: Some(String::from("/home/robert/projects/rcalc")),
+                    gitea_url: None,
+                    owner: Some(String::from("jamis")),
+                    repo: Some(String::from("rcalc")),
+                    token: None,
+                },
+                PartialConfig {
+                    project_path: Some(String::from("/home/robert/projects/rcalc-builders")),
+                    gitea_url: None,
+                    owner: Some(String::from("jamis")),
+                    repo: Some(String::from("rcalc")),
+                    token: None,
+                },
+            
+            ],
+        }
+    }
+
+    #[test]
+    fn read_single_prop() -> Result<()> {
+        let fx_input_str = "owner = \"dingus\"";
+        let fx_value = fx_input_str.parse::<Value>()?;
+        let fx_value = fx_value.as_table().ok_or(Error::NoSuchTable)?;
+        let expected = "dingus";
+
+        let res = get_property(&fx_value, String::from("owner"))?;
+        assert_eq!(res, expected);
+        Ok(())
+    }
+
+    // The property is given the value of empty-string `""`
+    #[test]
+    fn read_single_prop_empty_quotes() -> Result<()> {
+        let fx_input_str = "owner = \"\"";
+        let fx_value = fx_input_str.parse::<Value>()?;
+        let fx_value = fx_value.as_table().ok_or(Error::NoSuchTable)?;
+        let expected = "";
+
+        let res = get_property(&fx_value, String::from("owner"))?;
+        assert_eq!(res, expected);
+        Ok(())
+    }
+
+    #[test]
+    fn read_table() -> Result<()> {
+        let fx_input_str = "[tab]\nwith_a_garbage = \"value\"";
+        let fx_value = fx_input_str.parse::<Value>()?;
+        let fx_value = fx_value.as_table().ok_or(Error::BadFormat)?;
+        let mut expected: Map<String, Value> = Map::new();
+        expected.insert(String::from("with_a_garbage"), Value::String(String::from("value")));
+
+        let res = get_table(&fx_value, String::from("tab"))?;
+        assert_eq!(res, &expected);
+        Ok(())
+    }
+
+    #[test]
+    fn read_config_string_ok() -> Result<()> {
+        let fx_sample_config_string = include_str!("../test_data/sample_config.toml");
+        let fx_expected_struct = gen_expected_struct();
+        let conf = read_conf_str(fx_sample_config_string)?;
+        
+        assert_eq!(conf, fx_expected_struct);
+        Ok(())
+    }
+
+    /* TODO: Improve semantics around reading an empty string
+    An empty config string will result in Error::NoSuchTable when "[all]"
+    is retrieved. But this will *also* happen when other configs are present,
+    but "[all]" isn't. Do I treat these as valid configurations, using some
+    hard-coded default as the fallback? Or do I reject configs that don't have
+    an all-table?
+     */
+    #[test]
+    fn read_config_string_empty() {
+        let fx_sample_cfg = "";
+        let conf = read_conf_str(fx_sample_cfg);
+        assert!(conf.is_err());
+    }
+
+    #[test]
+    // File exists and has valid configuration.
+    fn load_from_file_ok() -> Result<()> {
+        let conf = load_from_file("test_data/sample_config.toml")?;
+        assert_eq!(conf, gen_expected_struct());
+        Ok(())
+    }
+
+    #[test]
+    // File does not exist.
+    fn load_from_file_missing() -> Result<()> {
+        let res = load_from_file("test_data/doesnt_exist.toml");
+        let err = res.unwrap_err();
+        assert_eq!(err, Error::CouldntReadFile);
+        Ok(())
+    }
+
+    #[test]
+    // File exists but has garbage inside.
+    // TODO: This bumps against the same semantic issue as the todo note on
+    // the 'read_config_string_empty' test
+    fn load_from_file_bad() {
+        let res = load_from_file("test_data/missing_all_table.toml");
+        assert!(res.is_err());
+    }
+}

src/lib.rs

@@ -2,6 +2,7 @@ use serde::{Deserialize, Serialize};
 
 pub mod api;
 pub mod cli;
+pub mod config;
 pub mod structs;
 
 #[derive(Debug, Deserialize, Serialize)]

test_data/missing_all_table.toml

@@ -0,0 +1,5 @@
+# There must be an "[all]" table or the loader will reject the config file.
+
+["/some/other/path"]
+gitea_url = "fake-url"
+

test_data/sample_config.toml

@@ -0,0 +1,15 @@
+[all]
+gitea_url = "http://localhost:3000"
+token = "fake-token"
+
+["/home/robert/projects/gt-tool"]
+owner = "robert"
+repo = "gt-tool"
+
+["/home/robert/projects/rcalc"]
+owner = "jamis"
+repo = "rcalc"
+
+["/home/robert/projects/rcalc-builders"]
+owner = "jamis"
+repo = "rcalc"