feat(functional): add trim_start and assoc (#779)

7 files changed, 110 insertions, 6 deletions

diff --git a/lua/mason-core/functional/init.lua b/lua/mason-core/functional/init.lua
index ee185e8b..837f9558 100644
--- a/lua/mason-core/functional/init.lua
+++ b/lua/mason-core/functional/init.lua
@@ -99,6 +99,7 @@ _.format = string.format
 _.split = string.split
 _.gsub = string.gsub
 _.trim = string.trim
+_.trim_start = string.trim_start
 _.dedent = string.dedent
 _.starts_with = string.starts_with
 _.to_upper = string.to_upper
@@ -117,6 +118,7 @@ _.invert = tbl.invert
 _.evolve = tbl.evolve
 _.merge_left = tbl.merge_left
 _.dissoc = tbl.dissoc
+_.assoc = tbl.assoc
 
 ---@module "mason-core.functional.type"
 local typ = lazy_require "mason-core.functional.type"
diff --git a/lua/mason-core/functional/relation.lua b/lua/mason-core/functional/relation.lua
index b6ba92b7..1561b030 100644
--- a/lua/mason-core/functional/relation.lua
+++ b/lua/mason-core/functional/relation.lua
@@ -18,7 +18,9 @@ end, 3)
 ---@param path any[]
 ---@param tbl table
 _.path_satisfies = fun.curryN(function(predicate, path, tbl)
-    return predicate(vim.tbl_get(tbl, unpack(path)))
+    -- see https://github.com/neovim/neovim/pull/21426
+    local value = vim.tbl_get(tbl, unpack(path))
+    return predicate(value)
 end, 3)
 
 ---@param a number
diff --git a/lua/mason-core/functional/string.lua b/lua/mason-core/functional/string.lua
index 8c66dbc0..2d53a5b6 100644
--- a/lua/mason-core/functional/string.lua
+++ b/lua/mason-core/functional/string.lua
@@ -85,4 +85,15 @@ _.to_lower = function(str)
     return str:lower()
 end
 
+---@param pattern string
+---@param str string
+_.trim_start = fun.curryN(function(pattern, str)
+    for i = 1, #str do
+        if not str:sub(i, i):match(pattern) then
+            return str:sub(i)
+        end
+    end
+    return str
+end, 2)
+
 return _
diff --git a/lua/mason-core/functional/table.lua b/lua/mason-core/functional/table.lua
index 276a3180..26db162b 100644
--- a/lua/mason-core/functional/table.lua
+++ b/lua/mason-core/functional/table.lua
@@ -24,7 +24,9 @@ end, 2)
 ---@param path any[]
 ---@param tbl table
 _.path = fun.curryN(function(path, tbl)
-    return vim.tbl_get(tbl, unpack(path))
+    -- see https://github.com/neovim/neovim/pull/21426
+    local value = vim.tbl_get(tbl, unpack(path))
+    return value
 end, 2)
 
 ---@generic T, U
@@ -97,10 +99,21 @@ _.merge_left = fun.curryN(function(left, right)
     return vim.tbl_extend("force", right, left)
 end, 2)
 
----@generic T : table
----@param key any
----@param tbl T
----@return T
+---@generic K, V
+---@param key K
+---@param value V
+---@param tbl table<K, V>
+---@return table<K, V>
+_.assoc = fun.curryN(function(key, value, tbl)
+    local res = shallow_clone(tbl)
+    res[key] = value
+    return res
+end, 3)
+
+---@generic K, V
+---@param key K
+---@param tbl table<K, V>
+---@return table<K, V>
 _.dissoc = fun.curryN(function(key, tbl)
     local res = shallow_clone(tbl)
     res[key] = nil
diff --git a/tests/mason-core/functional/list_spec.lua b/tests/mason-core/functional/list_spec.lua
index 7c3d8cfb..6c14e5a9 100644
--- a/tests/mason-core/functional/list_spec.lua
+++ b/tests/mason-core/functional/list_spec.lua
@@ -265,3 +265,39 @@ describe("functional: list", function()
         assert.spy(add).was_called_with(10, 5)
     end)
 end)
+
+describe("list immutability", function()
+    it("should not mutate lists", function()
+        local og_list = setmetatable({ "a", "b", "c" }, {
+            __newindex = function()
+                error "Tried to newindex"
+            end,
+        })
+
+        _.reverse(og_list)
+        _.list_copy(og_list)
+        _.filter(_.F, og_list)
+        _.map(_.to_upper, og_list)
+        _.filter_map(_.always(Optional.empty()), og_list)
+        _.each(_.length, og_list)
+        _.concat(og_list, { "d", "e" })
+        _.append("d", og_list)
+        _.prepend("0", og_list)
+        _.zip_table({ "first", "second", "third" }, og_list)
+        _.nth(1, og_list)
+        _.head(og_list)
+        _.last(og_list)
+        _.length(og_list)
+        _.flatten(og_list)
+        _.sort_by(_.identity, og_list)
+        _.uniq_by(_.identity, og_list)
+        _.join(".", og_list)
+        _.partition(_.equals "a", og_list)
+        _.take(2, og_list)
+        _.drop(2, og_list)
+        _.drop_last(2, og_list)
+        _.reduce(_.concat, "", og_list)
+
+        assert.same({ "a", "b", "c" }, og_list)
+    end)
+end)
diff --git a/tests/mason-core/functional/string_spec.lua b/tests/mason-core/functional/string_spec.lua
index 7bbe06c5..02062f4c 100644
--- a/tests/mason-core/functional/string_spec.lua
+++ b/tests/mason-core/functional/string_spec.lua
@@ -50,4 +50,12 @@ Ipsum
         assert.equals("HELLO!", _.to_upper "Hello!")
         assert.equals("hello!", _.to_lower "Hello!")
     end)
+
+    it("trim strings", function()
+        assert.equals("HELLO!", _.trim "   HELLO!  ")
+    end)
+
+    it("trim_starts strings", function()
+        assert.equals("HELLO!  ", _.trim_start("%s", "	   HELLO!  "))
+    end)
 end)
diff --git a/tests/mason-core/functional/table_spec.lua b/tests/mason-core/functional/table_spec.lua
index 357f7120..8ffedeb1 100644
--- a/tests/mason-core/functional/table_spec.lua
+++ b/tests/mason-core/functional/table_spec.lua
@@ -111,4 +111,36 @@ describe("functional: table", function()
             c = "c",
         }, _.dissoc("b", { a = "a", b = "b", c = "c" }))
     end)
+
+    it("should assoc keys", function()
+        assert.same({
+            a = "a",
+            b = "b",
+            c = "c",
+        }, _.assoc("b", "b", { a = "a", c = "c" }))
+    end)
+end)
+
+describe("table immutability", function()
+    it("should not mutate tables", function()
+        local og_table = setmetatable({ key = "value", imagination = "poor", hotel = "trivago" }, {
+            __newindex = function()
+                error "Tried to newindex"
+            end,
+        })
+
+        _.prop("hotel", og_table)
+        _.path({ "hotel" }, og_table)
+        _.pick({ "hotel" }, og_table)
+        _.keys(og_table)
+        _.size(og_table)
+        _.from_pairs(_.to_pairs(og_table))
+        _.invert(og_table)
+        _.evolve({ hotel = _.to_upper }, og_table)
+        _.merge_left(og_table, {})
+        _.assoc("new", "value", og_table)
+        _.dissoc("hotel", og_table)
+
+        assert.same({ key = "value", imagination = "poor", hotel = "trivago" }, og_table)
+    end)
 end)