convert string interpolation tokens to uast:String; addresses #21

Signed-off-by: Denys Smirnov <denys@sourced.tech>

Author: Denys Smirnov

driver/normalizer/normalizer.go

@@ -486,6 +486,27 @@ var Normalizers = []Mapping{
 		},
 	)),
 
+	// A string literal part of the interpolation expression.
+	MapSemantic("InterpolatedStringTextToken", uast.String{}, MapObj(
+		Obj{
+			// trivia == whitespace; can safely drop it
+			"LeadingTrivia":  Arr(),
+			"TrailingTrivia": Arr(),
+
+			"IsMissing": Bool(false),
+
+			// contains escaped value, we don't need it in canonical UAST
+			"Text": Any(),
+
+			// both values are the same
+			"Value":     Var("val"),
+			"ValueText": Var("val"),
+		},
+		Obj{
+			"Value": Var("val"),
+		},
+	)),
+
 	MapSemantic("TrueLiteralExpression", uast.Bool{}, MapObj(
 		Obj{
 			"Token": Obj{

fixtures/issue_18.cs.sem.uast

@@ -2128,8 +2128,7 @@
                                                                         },
                                                                         IsMissing: false,
                                                                         IsStructuredTrivia: false,
-                                                                        TextToken: { '@type': "csharp:InterpolatedStringTextToken",
-                                                                           '@role': [Incomplete, String],
+                                                                        TextToken: { '@type': "uast:String",
                                                                            '@pos': { '@type': "uast:Positions",
                                                                               start: { '@type': "uast:Position",
                                                                                  offset: 2124,
@@ -2142,12 +2141,8 @@
                                                                                  col: 28,
                                                                               },
                                                                            },
-                                                                           IsMissing: false,
-                                                                           LeadingTrivia: [],
-                                                                           Text: "\\\"[",
-                                                                           TrailingTrivia: [],
+                                                                           Format: "",
                                                                            Value: "\"[",
-                                                                           ValueText: "\"[",
                                                                         },
                                                                      },
                                                                      { '@type': "csharp:Interpolation",
@@ -2242,8 +2237,7 @@
                                                                         },
                                                                         IsMissing: false,
                                                                         IsStructuredTrivia: false,
-                                                                        TextToken: { '@type': "csharp:InterpolatedStringTextToken",
-                                                                           '@role': [Incomplete, String],
+                                                                        TextToken: { '@type': "uast:String",
                                                                            '@pos': { '@type': "uast:Positions",
                                                                               start: { '@type': "uast:Position",
                                                                                  offset: 2133,
@@ -2256,12 +2250,8 @@
                                                                                  col: 37,
                                                                               },
                                                                            },
-                                                                           IsMissing: false,
-                                                                           LeadingTrivia: [],
-                                                                           Text: "]\\\"",
-                                                                           TrailingTrivia: [],
+                                                                           Format: "",
                                                                            Value: "]\"",
-                                                                           ValueText: "]\"",
                                                                         },
                                                                      },
                                                                   ],