Add tests for the parsing logic

1 files changed, 164 insertions, 0 deletions

diff --git a/src/docker.rs b/src/docker.rs
new file mode 100644
index 0000000..3af3be5
--- /dev/null
+++ b/src/docker.rs
@@ -0,0 +1,164 @@
+use std::ops::Range;
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct DockerRef {
+    pub registry: Option<Range<usize>>,
+    pub image: Range<usize>,
+    pub tag: Option<Range<usize>>,
+    pub digest: Option<Range<usize>>,
+}
+
+impl DockerRef {
+    pub fn parse(content: &str, chunk: &Range<usize>) -> DockerRef {
+        let mut string_range = chunk.clone();
+
+        let mut digest = None;
+        if let Some(idx) = content[string_range.clone()].rfind("@") {
+            digest = Some(string_range.start+idx+1..string_range.end);
+            string_range.end = string_range.start+idx;
+        }
+
+        let mut tag = None;
+        if let Some(idx) = content[string_range.clone()].rfind(":") {
+            tag = Some(string_range.start+idx+1..string_range.end);
+            string_range.end = string_range.start+idx;
+        }
+
+        let mut registry = None;
+        let image;
+        if let Some(idx) = content[string_range.clone()].find("/") {
+            let head = &content[string_range.clone()][..idx];
+            if head.contains(":") || head.contains(".") {
+                registry = Some(string_range.start..string_range.start+idx);
+                image = string_range.start+idx+1..string_range.end;
+            } else {
+                registry = None;
+                image = string_range;
+            }
+        } else {
+            image = string_range;
+        }
+
+        return DockerRef {
+            registry,
+            image,
+            tag,
+            digest,
+        };
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn image_only() {
+        let input = "nginx";
+        let r = DockerRef::parse(input, &(0..input.len()));
+
+        assert_eq!(r.registry, None);
+        assert_eq!(&input[r.image], "nginx");
+        assert_eq!(r.tag, None);
+        assert_eq!(r.digest, None);
+    }
+
+    #[test]
+    fn image_with_tag() {
+        let input = "nginx:1.21";
+        let r = DockerRef::parse(input, &(0..input.len()));
+
+        assert_eq!(r.registry, None);
+        assert_eq!(&input[r.image], "nginx");
+        assert_eq!(&input[r.tag.unwrap()], "1.21");
+        assert_eq!(r.digest, None);
+    }
+
+    #[test]
+    fn image_with_org() {
+        let input = "myorg/nginx:1.21";
+        let r = DockerRef::parse(input, &(0..input.len()));
+
+        assert_eq!(r.registry, None);
+        assert_eq!(&input[r.image], "myorg/nginx");
+        assert_eq!(&input[r.tag.unwrap()], "1.21");
+        assert_eq!(r.digest, None);
+    }
+
+    #[test]
+    fn registry_detected_by_dot() {
+        let input = "registry.io/nginx:1.21";
+        let r = DockerRef::parse(input, &(0..input.len()));
+
+        assert_eq!(&input[r.registry.unwrap()], "registry.io");
+        assert_eq!(&input[r.image], "nginx");
+        assert_eq!(&input[r.tag.unwrap()], "1.21");
+        assert_eq!(r.digest, None);
+    }
+
+    #[test]
+    fn registry_detected_by_port() {
+        let input = "localhost:5000/nginx:1.21";
+        let r = DockerRef::parse(input, &(0..input.len()));
+
+        assert_eq!(&input[r.registry.unwrap()], "localhost:5000");
+        assert_eq!(&input[r.image], "nginx");
+        assert_eq!(&input[r.tag.unwrap()], "1.21");
+        assert_eq!(r.digest, None);
+    }
+
+    #[test]
+    fn digest_without_tag() {
+        let input = "nginx@sha256:abc123";
+        let r = DockerRef::parse(input, &(0..input.len()));
+
+        assert_eq!(r.registry, None);
+        assert_eq!(&input[r.image], "nginx");
+        assert_eq!(r.tag, None);
+        assert_eq!(&input[r.digest.unwrap()], "sha256:abc123");
+    }
+
+    #[test]
+    fn tag_and_digest() {
+        let input = "nginx:1.21@sha256:abc123";
+        let r = DockerRef::parse(input, &(0..input.len()));
+
+        assert_eq!(r.registry, None);
+        assert_eq!(&input[r.image], "nginx");
+        assert_eq!(&input[r.tag.unwrap()], "1.21");
+        assert_eq!(&input[r.digest.unwrap()], "sha256:abc123");
+    }
+
+    #[test]
+    fn full_reference() {
+        let input = "registry.io/myorg/nginx:1.21@sha256:abc123";
+        let r = DockerRef::parse(input, &(0..input.len()));
+
+        assert_eq!(&input[r.registry.unwrap()], "registry.io");
+        assert_eq!(&input[r.image], "myorg/nginx");
+        assert_eq!(&input[r.tag.unwrap()], "1.21");
+        assert_eq!(&input[r.digest.unwrap()], "sha256:abc123");
+    }
+
+    #[test]
+    fn deep_image_path() {
+        let input = "registry.io/org/team/project/nginx:1.21";
+        let r = DockerRef::parse(input, &(0..input.len()));
+
+        assert_eq!(&input[r.registry.unwrap()], "registry.io");
+        assert_eq!(&input[r.image], "org/team/project/nginx");
+        assert_eq!(&input[r.tag.unwrap()], "1.21");
+        assert_eq!(r.digest, None);
+    }
+
+    #[test]
+    fn non_zero_offset() {
+        let input = "prefix registry.io/nginx:1.21 suffix";
+        let r = DockerRef::parse(input, &(7..29));
+
+        assert_eq!(&input[r.registry.unwrap()], "registry.io");
+        assert_eq!(&input[r.image], "nginx");
+        assert_eq!(&input[r.tag.unwrap()], "1.21");
+        assert_eq!(r.digest, None);
+    }
+}