feat(api): support optional parameters

packages/api/src/merge.ts

@@ -68,7 +68,7 @@ function _recursivelyExpandType(typeChecker: ts.TypeChecker, types: ts.Type[], s
         return createObjectType(typeChecker, ts.ObjectFlags.Anonymous)
     }
 
-    // TODO: move to type.getProperties()
+    // TODO: move to using type.getProperties() on the intersection type
     function recursiveMergeObjectIntersection(types: ts.ObjectType[], newType?: ObjectType) {
         newType ||= createAnonymousObjectType()
         const nameToSymbols = new Map<SymbolName, TSSymbol[]>()
@@ -93,7 +93,13 @@ function _recursivelyExpandType(typeChecker: ts.TypeChecker, types: ts.Type[], s
     }
 
     function mergeIntersectedPropertySymbols(symbols: TSSymbol[], name: SymbolName): TSSymbol {
-        const propertySymbol = createSymbol(ts.SymbolFlags.Property, name, 1 << 18)
+        let symbolFlags = ts.SymbolFlags.Property
+
+        if(symbols.every(s => s.flags & ts.SymbolFlags.Optional)) {
+            symbolFlags |= ts.SymbolFlags.Optional
+        }
+
+        const propertySymbol = createSymbol(symbolFlags, name, 1 << 18)
 
         const types = symbols.map(s => getSymbolType(typeChecker, s))
 

packages/api/src/tree.ts

@@ -158,6 +158,7 @@ function getIndexInfo(indexInfo: ts.IndexInfo, ctx: TypeTreeContext): IndexInfo
 function getSymbolInfo(symbol: ts.Symbol): SymbolInfo {
     return {
         name: symbol.getName(),
+        flags: symbol.getFlags()
     }
 }
 

packages/api/src/types.ts

@@ -1,7 +1,8 @@
 import ts from "typescript"
 
 export type SymbolInfo = {
-    name?: string,
+    name: string,
+    flags: number
 }
 
 export type IndexInfo = {

tests/baselines/reference/function.tree

@@ -3,10 +3,10 @@
 function func(a: string, b: number) {
     return "asd"
 }
-> function --- {"kind":"object","signatures":[{"parameters":[{"kind":"primitive","primitive":"string","symbolMeta":{"name":"a"},"id":15},{"kind":"primitive","primitive":"number","symbolMeta":{"name":"b"},"id":16}],"returnType":{"kind":"reference","id":15}}],"properties":[],"indexInfos":[],"symbolMeta":{"name":"func"},"id":86}
-> func --- {"kind":"object","signatures":[{"parameters":[{"kind":"primitive","primitive":"string","symbolMeta":{"name":"a"},"id":15},{"kind":"primitive","primitive":"number","symbolMeta":{"name":"b"},"id":16}],"returnType":{"kind":"reference","id":15}}],"properties":[],"indexInfos":[],"symbolMeta":{"name":"func"},"id":86}
+> function --- {"kind":"object","signatures":[{"parameters":[{"kind":"primitive","primitive":"string","symbolMeta":{"name":"a","flags":1},"id":15},{"kind":"primitive","primitive":"number","symbolMeta":{"name":"b","flags":1},"id":16}],"returnType":{"kind":"reference","id":15}}],"properties":[],"indexInfos":[],"symbolMeta":{"name":"func","flags":16},"id":86}
+> func --- {"kind":"object","signatures":[{"parameters":[{"kind":"primitive","primitive":"string","symbolMeta":{"name":"a","flags":1},"id":15},{"kind":"primitive","primitive":"number","symbolMeta":{"name":"b","flags":1},"id":16}],"returnType":{"kind":"reference","id":15}}],"properties":[],"indexInfos":[],"symbolMeta":{"name":"func","flags":16},"id":86}
 > a: string, b: number
 > a: string
-> a --- {"kind":"primitive","primitive":"string","symbolMeta":{"name":"a"},"id":15}
+> a --- {"kind":"primitive","primitive":"string","symbolMeta":{"name":"a","flags":1},"id":15}
 > b: number
-> b --- {"kind":"primitive","primitive":"number","symbolMeta":{"name":"b"},"id":16}
+> b --- {"kind":"primitive","primitive":"number","symbolMeta":{"name":"b","flags":1},"id":16}

tests/baselines/reference/lambda.tree

@@ -1,22 +1,22 @@
 === lambda.ts ===
 
 type f = (arg1: string, arg2: boolean) => void
-> f --- {"kind":"object","signatures":[{"parameters":[{"kind":"primitive","primitive":"string","symbolMeta":{"name":"arg1"},"id":15},{"kind":"primitive","primitive":"boolean","symbolMeta":{"name":"arg2"},"id":22}],"returnType":{"kind":"primitive","primitive":"void","id":24}}],"properties":[],"indexInfos":[],"symbolMeta":{"name":"f"},"id":86}
+> f --- {"kind":"object","signatures":[{"parameters":[{"kind":"primitive","primitive":"string","symbolMeta":{"name":"arg1","flags":1},"id":15},{"kind":"primitive","primitive":"boolean","symbolMeta":{"name":"arg2","flags":1},"id":22}],"returnType":{"kind":"primitive","primitive":"void","id":24}}],"properties":[],"indexInfos":[],"symbolMeta":{"name":"f","flags":524288},"id":86}
 > (arg1: string, arg2: boolean) => void
 > arg1: string, arg2: boolean
 > arg1: string
-> arg1 --- {"kind":"primitive","primitive":"string","symbolMeta":{"name":"arg1"},"id":15}
+> arg1 --- {"kind":"primitive","primitive":"string","symbolMeta":{"name":"arg1","flags":1},"id":15}
 > arg2: boolean
-> arg2 --- {"kind":"primitive","primitive":"boolean","symbolMeta":{"name":"arg2"},"id":22}
-> => --- {"kind":"primitive","primitive":"any","symbolMeta":{"name":"__type"},"id":4}
+> arg2 --- {"kind":"primitive","primitive":"boolean","symbolMeta":{"name":"arg2","flags":1},"id":22}
+> => --- {"kind":"primitive","primitive":"any","symbolMeta":{"name":"__type","flags":2048},"id":4}
 
 type t = { a: string } | f
-> t --- {"kind":"union","types":[{"kind":"object","signatures":[{"parameters":[{"kind":"primitive","primitive":"string","symbolMeta":{"name":"arg1"},"id":15},{"kind":"primitive","primitive":"boolean","symbolMeta":{"name":"arg2"},"id":22}],"returnType":{"kind":"primitive","primitive":"void","id":24}}],"properties":[],"indexInfos":[],"symbolMeta":{"name":"__type"},"id":86},{"kind":"object","signatures":[],"properties":[{"kind":"reference","symbolMeta":{"name":"a"},"id":15}],"indexInfos":[],"symbolMeta":{"name":"__type"},"id":87}],"symbolMeta":{"name":"t"},"id":88}
+> t --- {"kind":"union","types":[{"kind":"object","signatures":[{"parameters":[{"kind":"primitive","primitive":"string","symbolMeta":{"name":"arg1","flags":1},"id":15},{"kind":"primitive","primitive":"boolean","symbolMeta":{"name":"arg2","flags":1},"id":22}],"returnType":{"kind":"primitive","primitive":"void","id":24}}],"properties":[],"indexInfos":[],"symbolMeta":{"name":"__type","flags":2048},"id":86},{"kind":"object","signatures":[],"properties":[{"kind":"reference","symbolMeta":{"name":"a","flags":4},"id":15}],"indexInfos":[],"symbolMeta":{"name":"__type","flags":2048},"id":87}],"symbolMeta":{"name":"t","flags":524288},"id":88}
 > { a: string } | f
 > { a: string } | f
 > { a: string }
 > a: string
 > a: string
-> a --- {"kind":"primitive","primitive":"string","symbolMeta":{"name":"a"},"id":15}
+> a --- {"kind":"primitive","primitive":"string","symbolMeta":{"name":"a","flags":4},"id":15}
 > f
-> f --- {"kind":"object","signatures":[{"parameters":[{"kind":"primitive","primitive":"string","symbolMeta":{"name":"arg1"},"id":15},{"kind":"primitive","primitive":"boolean","symbolMeta":{"name":"arg2"},"id":22}],"returnType":{"kind":"primitive","primitive":"void","id":24}}],"properties":[],"indexInfos":[],"symbolMeta":{"name":"f"},"id":86}
+> f --- {"kind":"object","signatures":[{"parameters":[{"kind":"primitive","primitive":"string","symbolMeta":{"name":"arg1","flags":1},"id":15},{"kind":"primitive","primitive":"boolean","symbolMeta":{"name":"arg2","flags":1},"id":22}],"returnType":{"kind":"primitive","primitive":"void","id":24}}],"properties":[],"indexInfos":[],"symbolMeta":{"name":"f","flags":524288},"id":86}

tests/baselines/reference/mapped.tree

@@ -1,10 +1,10 @@
 === mapped.ts ===
 
 type mapped = { [index: string]: number }
-> mapped --- {"kind":"object","signatures":[],"properties":[],"indexInfos":[{"keyType":{"kind":"primitive","primitive":"string","id":15},"type":{"kind":"primitive","primitive":"number","id":16}}],"symbolMeta":{"name":"mapped"},"id":86}
+> mapped --- {"kind":"object","signatures":[],"properties":[],"indexInfos":[{"keyType":{"kind":"primitive","primitive":"string","id":15},"type":{"kind":"primitive","primitive":"number","id":16}}],"symbolMeta":{"name":"mapped","flags":524288},"id":86}
 > { [index: string]: number }
 > [index: string]: number
 > [index: string]: number
 > index: string
 > index: string
-> index --- {"kind":"primitive","primitive":"string","symbolMeta":{"name":"index"},"id":15}
+> index --- {"kind":"primitive","primitive":"string","symbolMeta":{"name":"index","flags":1},"id":15}

tests/baselines/reference/partial.merged.types

@@ -0,0 +1,17 @@
+=== partial.ts ===
+
+type partialUnion = Partial<{a: string}|{b: string}>
+> partialUnion --- { a?: string; } | { b?: string; }
+> Partial<{a: string}|{b: string}>
+> Partial --- {}
+> {a: string}|{b: string}
+> {a: string}|{b: string}
+> {a: string}|{b: string}
+> {a: string}
+> a: string
+> a: string
+> a --- string
+> {b: string}
+> b: string
+> b: string
+> b --- string

tests/baselines/reference/partial.tree

@@ -0,0 +1,17 @@
+=== partial.ts ===
+
+type partialUnion = Partial<{a: string}|{b: string}>
+> partialUnion --- {"kind":"union","types":[{"kind":"object","signatures":[],"properties":[{"kind":"primitive","primitive":"string","symbolMeta":{"name":"a","flags":50331652},"id":15}],"indexInfos":[],"symbolMeta":{"name":"__type","flags":2048},"id":93},{"kind":"object","signatures":[],"properties":[{"kind":"reference","symbolMeta":{"name":"b","flags":50331652},"id":15}],"indexInfos":[],"symbolMeta":{"name":"__type","flags":2048},"id":95}],"symbolMeta":{"name":"partialUnion","flags":524288},"id":97}
+> Partial<{a: string}|{b: string}>
+> Partial --- {"kind":"object","signatures":[],"properties":[],"indexInfos":[],"symbolMeta":{"name":"Partial","flags":524288},"id":86}
+> {a: string}|{b: string}
+> {a: string}|{b: string}
+> {a: string}|{b: string}
+> {a: string}
+> a: string
+> a: string
+> a --- {"kind":"primitive","primitive":"string","symbolMeta":{"name":"a","flags":4},"id":15}
+> {b: string}
+> b: string
+> b: string
+> b --- {"kind":"primitive","primitive":"string","symbolMeta":{"name":"b","flags":4},"id":15}

tests/baselines/reference/pick.tree

@@ -1,58 +1,58 @@
 === pick.ts ===
 
 type t = { a: "b", c: "d", d: { a: "b" } }
-> t --- {"kind":"object","signatures":[],"properties":[{"kind":"string_literal","value":"b","symbolMeta":{"name":"a"},"id":87},{"kind":"string_literal","value":"d","symbolMeta":{"name":"c"},"id":89},{"kind":"object","signatures":[],"properties":[{"kind":"reference","symbolMeta":{"name":"a"},"id":87}],"indexInfos":[],"symbolMeta":{"name":"d"},"id":91}],"indexInfos":[],"symbolMeta":{"name":"t"},"id":86}
+> t --- {"kind":"object","signatures":[],"properties":[{"kind":"string_literal","value":"b","symbolMeta":{"name":"a","flags":4},"id":87},{"kind":"string_literal","value":"d","symbolMeta":{"name":"c","flags":4},"id":89},{"kind":"object","signatures":[],"properties":[{"kind":"reference","symbolMeta":{"name":"a","flags":4},"id":87}],"indexInfos":[],"symbolMeta":{"name":"d","flags":4},"id":91}],"indexInfos":[],"symbolMeta":{"name":"t","flags":524288},"id":86}
 > { a: "b", c: "d", d: { a: "b" } }
 > a: "b", c: "d", d: { a: "b" }
 > a: "b",
-> a --- {"kind":"string_literal","value":"b","symbolMeta":{"name":"a"},"id":87}
+> a --- {"kind":"string_literal","value":"b","symbolMeta":{"name":"a","flags":4},"id":87}
 > c: "d",
-> c --- {"kind":"string_literal","value":"d","symbolMeta":{"name":"c"},"id":89}
+> c --- {"kind":"string_literal","value":"d","symbolMeta":{"name":"c","flags":4},"id":89}
 > d: { a: "b" }
-> d --- {"kind":"object","signatures":[],"properties":[{"kind":"string_literal","value":"b","symbolMeta":{"name":"a"},"id":87}],"indexInfos":[],"symbolMeta":{"name":"d"},"id":91}
+> d --- {"kind":"object","signatures":[],"properties":[{"kind":"string_literal","value":"b","symbolMeta":{"name":"a","flags":4},"id":87}],"indexInfos":[],"symbolMeta":{"name":"d","flags":4},"id":91}
 > { a: "b" }
 > a: "b"
 > a: "b"
-> a --- {"kind":"string_literal","value":"b","symbolMeta":{"name":"a"},"id":87}
+> a --- {"kind":"string_literal","value":"b","symbolMeta":{"name":"a","flags":4},"id":87}
 
 type p = Pick<t, "a"|"d"> & {b: "asd", d: { b: "c" }}
-> p --- {"kind":"object","properties":[{"kind":"object","properties":[{"kind":"string_literal","value":"b","symbolMeta":{"name":"a"},"id":87},{"kind":"string_literal","value":"c","symbolMeta":{"name":"b"},"id":107}],"symbolMeta":{"name":"d"},"id":106},{"kind":"reference","symbolMeta":{"name":"a"},"id":87},{"kind":"string_literal","value":"asd","symbolMeta":{"name":"b"},"id":109}],"symbolMeta":{"name":"p"},"id":103}
+> p --- {"kind":"object","properties":[{"kind":"object","properties":[{"kind":"string_literal","value":"b","symbolMeta":{"name":"a","flags":4},"id":87},{"kind":"string_literal","value":"c","symbolMeta":{"name":"b","flags":4},"id":107}],"symbolMeta":{"name":"d","flags":33554436},"id":106},{"kind":"reference","symbolMeta":{"name":"a","flags":33554436},"id":87},{"kind":"string_literal","value":"asd","symbolMeta":{"name":"b","flags":4},"id":109}],"symbolMeta":{"name":"p","flags":524288},"id":103}
 > Pick<t, "a"|"d"> & {b: "asd", d: { b: "c" }}
 > Pick<t, "a"|"d"> & {b: "asd", d: { b: "c" }}
 > Pick<t, "a"|"d">
-> Pick --- {"kind":"object","signatures":[],"properties":[],"indexInfos":[],"symbolMeta":{"name":"Pick"},"id":92}
+> Pick --- {"kind":"object","signatures":[],"properties":[],"indexInfos":[],"symbolMeta":{"name":"Pick","flags":524288},"id":92}
 > t, "a"|"d"
 > t
-> t --- {"kind":"object","signatures":[],"properties":[{"kind":"string_literal","value":"b","symbolMeta":{"name":"a"},"id":87},{"kind":"string_literal","value":"d","symbolMeta":{"name":"c"},"id":89},{"kind":"object","signatures":[],"properties":[{"kind":"reference","symbolMeta":{"name":"a"},"id":87}],"indexInfos":[],"symbolMeta":{"name":"d"},"id":91}],"indexInfos":[],"symbolMeta":{"name":"t"},"id":86}
+> t --- {"kind":"object","signatures":[],"properties":[{"kind":"string_literal","value":"b","symbolMeta":{"name":"a","flags":4},"id":87},{"kind":"string_literal","value":"d","symbolMeta":{"name":"c","flags":4},"id":89},{"kind":"object","signatures":[],"properties":[{"kind":"reference","symbolMeta":{"name":"a","flags":4},"id":87}],"indexInfos":[],"symbolMeta":{"name":"d","flags":4},"id":91}],"indexInfos":[],"symbolMeta":{"name":"t","flags":524288},"id":86}
 > {b: "asd", d: { b: "c" }}
 > b: "asd", d: { b: "c" }
 > b: "asd",
-> b --- {"kind":"string_literal","value":"asd","symbolMeta":{"name":"b"},"id":109}
+> b --- {"kind":"string_literal","value":"asd","symbolMeta":{"name":"b","flags":4},"id":109}
 > d: { b: "c" }
-> d --- {"kind":"object","signatures":[],"properties":[{"kind":"string_literal","value":"c","symbolMeta":{"name":"b"},"id":107}],"indexInfos":[],"symbolMeta":{"name":"d"},"id":105}
+> d --- {"kind":"object","signatures":[],"properties":[{"kind":"string_literal","value":"c","symbolMeta":{"name":"b","flags":4},"id":107}],"indexInfos":[],"symbolMeta":{"name":"d","flags":4},"id":105}
 > { b: "c" }
 > b: "c"
 > b: "c"
-> b --- {"kind":"string_literal","value":"c","symbolMeta":{"name":"b"},"id":107}
+> b --- {"kind":"string_literal","value":"c","symbolMeta":{"name":"b","flags":4},"id":107}
 
 const test3: p = {a: "b", b: "asd", d: { a: "b", b: "c" }}
 > const test3: p = {a: "b", b: "asd", d: { a: "b", b: "c" }}
 > test3: p = {a: "b", b: "asd", d: { a: "b", b: "c" }}
 > test3: p = {a: "b", b: "asd", d: { a: "b", b: "c" }}
-> test3 --- {"kind":"object","properties":[{"kind":"object","properties":[{"kind":"string_literal","value":"b","symbolMeta":{"name":"a"},"id":87},{"kind":"string_literal","value":"c","symbolMeta":{"name":"b"},"id":107}],"symbolMeta":{"name":"d"},"id":106},{"kind":"reference","symbolMeta":{"name":"a"},"id":87},{"kind":"string_literal","value":"asd","symbolMeta":{"name":"b"},"id":109}],"symbolMeta":{"name":"test3"},"id":103}
+> test3 --- {"kind":"object","properties":[{"kind":"object","properties":[{"kind":"string_literal","value":"b","symbolMeta":{"name":"a","flags":4},"id":87},{"kind":"string_literal","value":"c","symbolMeta":{"name":"b","flags":4},"id":107}],"symbolMeta":{"name":"d","flags":33554436},"id":106},{"kind":"reference","symbolMeta":{"name":"a","flags":33554436},"id":87},{"kind":"string_literal","value":"asd","symbolMeta":{"name":"b","flags":4},"id":109}],"symbolMeta":{"name":"test3","flags":2},"id":103}
 > p
-> p --- {"kind":"object","properties":[{"kind":"object","properties":[{"kind":"string_literal","value":"b","symbolMeta":{"name":"a"},"id":87},{"kind":"string_literal","value":"c","symbolMeta":{"name":"b"},"id":107}],"symbolMeta":{"name":"d"},"id":106},{"kind":"reference","symbolMeta":{"name":"a"},"id":87},{"kind":"string_literal","value":"asd","symbolMeta":{"name":"b"},"id":109}],"symbolMeta":{"name":"p"},"id":103}
+> p --- {"kind":"object","properties":[{"kind":"object","properties":[{"kind":"string_literal","value":"b","symbolMeta":{"name":"a","flags":4},"id":87},{"kind":"string_literal","value":"c","symbolMeta":{"name":"b","flags":4},"id":107}],"symbolMeta":{"name":"d","flags":33554436},"id":106},{"kind":"reference","symbolMeta":{"name":"a","flags":33554436},"id":87},{"kind":"string_literal","value":"asd","symbolMeta":{"name":"b","flags":4},"id":109}],"symbolMeta":{"name":"p","flags":524288},"id":103}
 > {a: "b", b: "asd", d: { a: "b", b: "c" }}
 > a: "b", b: "asd", d: { a: "b", b: "c" }
 > a: "b"
-> a --- {"kind":"string_literal","value":"b","symbolMeta":{"name":"a"},"id":88}
+> a --- {"kind":"string_literal","value":"b","symbolMeta":{"name":"a","flags":4},"id":88}
 > b: "asd"
-> b --- {"kind":"string_literal","value":"asd","symbolMeta":{"name":"b"},"id":110}
+> b --- {"kind":"string_literal","value":"asd","symbolMeta":{"name":"b","flags":4},"id":110}
 > d: { a: "b", b: "c" }
-> d --- {"kind":"object","signatures":[],"properties":[{"kind":"string_literal","value":"b","symbolMeta":{"name":"a"},"id":88},{"kind":"string_literal","value":"c","symbolMeta":{"name":"b"},"id":108}],"indexInfos":[],"symbolMeta":{"name":"d"},"id":111}
+> d --- {"kind":"object","signatures":[],"properties":[{"kind":"string_literal","value":"b","symbolMeta":{"name":"a","flags":33554436},"id":88},{"kind":"string_literal","value":"c","symbolMeta":{"name":"b","flags":33554436},"id":108}],"indexInfos":[],"symbolMeta":{"name":"d","flags":4},"id":111}
 > { a: "b", b: "c" }
 > a: "b", b: "c"
 > a: "b"
-> a --- {"kind":"string_literal","value":"b","symbolMeta":{"name":"a"},"id":88}
+> a --- {"kind":"string_literal","value":"b","symbolMeta":{"name":"a","flags":4},"id":88}
 > b: "c"
-> b --- {"kind":"string_literal","value":"c","symbolMeta":{"name":"b"},"id":108}
+> b --- {"kind":"string_literal","value":"c","symbolMeta":{"name":"b","flags":4},"id":108}