From 3cf057b7f830a1e32b4d0503ecda335f6b52cea4 Mon Sep 17 00:00:00 2001
From: Oliver Linnarsson <oliver@lolo.company>
Date: Tue, 18 Jun 2024 16:11:44 +0200
Subject: [PATCH] feat: Improve DX for working with ctx

---
 src/handles/ctx.gleam          | 91 ++++++++++++++++++++++++++++++++++
 test/unit_tests/ctx_test.gleam | 78 +++++++++++++++++++++++++++++
 2 files changed, 169 insertions(+)
 create mode 100644 test/unit_tests/ctx_test.gleam

diff --git a/src/handles/ctx.gleam b/src/handles/ctx.gleam
index ddf6712..39cb79c 100644
--- a/src/handles/ctx.gleam
+++ b/src/handles/ctx.gleam
@@ -1,3 +1,7 @@
+import gleam/dict
+import gleam/dynamic
+import gleam/list
+
 pub type Prop {
   Prop(key: String, value: Value)
 }
@@ -10,3 +14,90 @@ pub type Value {
   Dict(value: List(Prop))
   List(value: List(Value))
 }
+
+/// Transforms String, Int, Float, Bool, List, & Dict to their coresponding ctx.Value type.
+/// 
+/// Anny other types will panic
+/// 
+/// ## Examples
+/// 
+/// ```gleam
+/// import handles/ctx
+/// 
+/// ctx.from("Hello World")
+/// // -> ctx.Str("Hello World")
+/// ```
+///
+/// ```gleam
+/// ctx.from(42)
+/// // -> ctx.Int(42)
+/// ```
+/// 
+/// ```gleam
+/// ctx.from(3.14)
+/// // -> ctx.Float(3.14)
+/// ```
+/// 
+/// ```gleam
+/// ctx.from([1, 2, 3])
+/// // -> ctx.List([ctx.Int(1), ctx.Int(2), ctx.Int(3)])
+/// ```
+/// 
+/// ```gleam
+/// ctx.from([
+///   42 |> dynamic.from,
+///   3.14 |> dynamic.from,
+///   "Hello" |> dynamic.from,
+/// ])
+/// // -> ctx.List([ctx.Int(42), ctx.Float(3.14), ctx.Str("Hello")])
+/// ```
+pub fn from(value: a) -> Value {
+  from_dynamic(value |> dynamic.from)
+}
+
+fn from_dynamic(value: dynamic.Dynamic) -> Value {
+  case value |> dynamic.classify {
+    "String" -> {
+      let assert Ok(val) = value |> dynamic.string
+      Str(val)
+    }
+    "Int" -> {
+      let assert Ok(val) = value |> dynamic.int
+      Int(val)
+    }
+    "Float" -> {
+      let assert Ok(val) = value |> dynamic.float
+      Float(val)
+    }
+    "Bool" -> {
+      let assert Ok(val) = value |> dynamic.bool
+      Bool(val)
+    }
+    "Dict" -> {
+      let assert Ok(val) =
+        value |> dynamic.dict(dynamic.string, dynamic.dynamic)
+      from_dict(val, from_dynamic)
+    }
+    "List" -> {
+      let assert Ok(val) = value |> dynamic.list(dynamic.dynamic)
+      from_list(val, from_dynamic)
+    }
+    _ -> panic as "Unable to construct ctx from dynamic value"
+  }
+}
+
+fn from_dict(
+  source: dict.Dict(String, a),
+  value_mapper: fn(a) -> Value,
+) -> Value {
+  source
+  |> dict.to_list
+  |> list.map(fn(it) { Prop(it.0, value_mapper(it.1)) })
+  |> Dict
+}
+
+fn from_list(source: List(a), value_mapper: fn(a) -> Value) -> Value {
+  source
+  |> list.map(value_mapper)
+  |> List
+}
diff --git a/test/unit_tests/ctx_test.gleam b/test/unit_tests/ctx_test.gleam
new file mode 100644
index 0000000..7eaec46
--- /dev/null
+++ b/test/unit_tests/ctx_test.gleam
@@ -0,0 +1,78 @@
+import gleam/dict
+import gleam/dynamic
+import gleam/iterator
+import gleeunit/should
+import handles/ctx
+import handles/internal/ctx_utils
+
+const expected_string = "expected"
+
+fn gen_levels(levels_to_go: Int) {
+  case levels_to_go {
+    0 -> ctx.Str(expected_string)
+    _ -> ctx.Dict([ctx.Prop("prop", gen_levels(levels_to_go - 1))])
+  }
+}
+
+pub fn drill_shallow_test() {
+  ctx.Dict([ctx.Prop("prop", ctx.Str(expected_string))])
+  |> ctx_utils.drill_ctx(["prop"], _)
+  |> should.be_ok
+  |> should.equal(ctx.Str(expected_string))
+}
+
+pub fn drill_deep_test() {
+  let depth = 100
+  iterator.repeat("prop")
+  |> iterator.take(depth)
+  |> iterator.to_list
+  |> ctx_utils.drill_ctx(gen_levels(depth))
+  |> should.be_ok
+  |> should.equal(ctx.Str(expected_string))
+}
+
+pub fn from_string_test() {
+  ctx.from("foo")
+  |> should.equal(ctx.Str("foo"))
+}
+
+pub fn from_int_test() {
+  ctx.from(42)
+  |> should.equal(ctx.Int(42))
+}
+
+pub fn from_float_test() {
+  ctx.from(3.14)
+  |> should.equal(ctx.Float(3.14))
+}
+
+pub fn from_bool_test() {
+  ctx.from(True)
+  |> should.equal(ctx.Bool(True))
+}
+
+pub fn from_list_test() {
+  ctx.from([1, 2, 3])
+  |> should.equal(ctx.List([ctx.Int(1), ctx.Int(2), ctx.Int(3)]))
+}
+
+pub fn from_dict_test() {
+  ctx.from(
+    dict.new()
+    |> dict.insert("first", 1)
+    |> dict.insert("second", 2)
+    |> dict.insert("third", 3),
+  )
+  |> should.equal(
+    ctx.Dict([
+      ctx.Prop("first", ctx.Int(1)),
+      ctx.Prop("second", ctx.Int(2)),
+      ctx.Prop("third", ctx.Int(3)),
+    ]),
+  )
+}
+
+pub fn from_mixed_types_test() {
+  ctx.from([42 |> dynamic.from, 3.14 |> dynamic.from, "Hello" |> dynamic.from])
+  |> should.equal(ctx.List([ctx.Int(42), ctx.Float(3.14), ctx.Str("Hello")]))
+}