diff --git a/tests/baselines/reference/APISample_compile.js b/tests/baselines/reference/APISample_compile.js
index b91a706aa45..83951d237a3 100644
--- a/tests/baselines/reference/APISample_compile.js
+++ b/tests/baselines/reference/APISample_compile.js
@@ -1384,14 +1384,14 @@ declare module "typescript" {
     }
     function tokenToString(t: SyntaxKind): string;
     function computeLineStarts(text: string): number[];
-    function getPositionFromLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;
-    function computePositionFromLineAndCharacter(lineStarts: number[], line: number, character: number): number;
+    function getPositionFromOneBasedLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;
+    function computePositionFromOneBasedLineAndCharacter(lineStarts: number[], line: number, character: number): number;
     function getLineStarts(sourceFile: SourceFile): number[];
-    function computeLineAndCharacterOfPosition(lineStarts: number[], position: number): {
+    function computeOneBasedLineAndCharacterOfPosition(lineStarts: number[], position: number): {
         line: number;
         character: number;
     };
-    function getLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;
+    function getOneBasedLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;
     function isWhiteSpace(ch: number): boolean;
     function isLineBreak(ch: number): boolean;
     function isOctalDigit(ch: number): boolean;
@@ -1471,7 +1471,7 @@ declare module "typescript" {
         getNamedDeclarations(): Declaration[];
         getLineAndCharacterFromPosition(pos: number): LineAndCharacter;
         getLineStarts(): number[];
-        getPositionFromLineAndCharacter(line: number, character: number): number;
+        getPositionFromOneBasedLineAndCharacter(line: number, character: number): number;
         update(newText: string, textChangeRange: TextChangeRange): SourceFile;
     }
     /**
diff --git a/tests/baselines/reference/APISample_compile.types b/tests/baselines/reference/APISample_compile.types
index ae53c666807..18b6f84c702 100644
--- a/tests/baselines/reference/APISample_compile.types
+++ b/tests/baselines/reference/APISample_compile.types
@@ -4368,15 +4368,15 @@ declare module "typescript" {
 >computeLineStarts : (text: string) => number[]
 >text : string
 
-    function getPositionFromLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;

->getPositionFromLineAndCharacter : (sourceFile: SourceFile, line: number, character: number) => number
+    function getPositionFromOneBasedLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;

+>getPositionFromOneBasedLineAndCharacter : (sourceFile: SourceFile, line: number, character: number) => number
 >sourceFile : SourceFile
 >SourceFile : SourceFile
 >line : number
 >character : number
 
-    function computePositionFromLineAndCharacter(lineStarts: number[], line: number, character: number): number;

->computePositionFromLineAndCharacter : (lineStarts: number[], line: number, character: number) => number
+    function computePositionFromOneBasedLineAndCharacter(lineStarts: number[], line: number, character: number): number;

+>computePositionFromOneBasedLineAndCharacter : (lineStarts: number[], line: number, character: number) => number
 >lineStarts : number[]
 >line : number
 >character : number
@@ -4386,8 +4386,8 @@ declare module "typescript" {
 >sourceFile : SourceFile
 >SourceFile : SourceFile
 
-    function computeLineAndCharacterOfPosition(lineStarts: number[], position: number): {

->computeLineAndCharacterOfPosition : (lineStarts: number[], position: number) => { line: number; character: number; }
+    function computeOneBasedLineAndCharacterOfPosition(lineStarts: number[], position: number): {

+>computeOneBasedLineAndCharacterOfPosition : (lineStarts: number[], position: number) => { line: number; character: number; }
 >lineStarts : number[]
 >position : number
 
@@ -4398,8 +4398,8 @@ declare module "typescript" {
 >character : number
 
     };

-    function getLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;

->getLineAndCharacterOfPosition : (sourceFile: SourceFile, position: number) => LineAndCharacter
+    function getOneBasedLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;

+>getOneBasedLineAndCharacterOfPosition : (sourceFile: SourceFile, position: number) => LineAndCharacter
 >sourceFile : SourceFile
 >SourceFile : SourceFile
 >position : number
@@ -4743,8 +4743,8 @@ declare module "typescript" {
         getLineStarts(): number[];

 >getLineStarts : () => number[]
 
-        getPositionFromLineAndCharacter(line: number, character: number): number;

->getPositionFromLineAndCharacter : (line: number, character: number) => number
+        getPositionFromOneBasedLineAndCharacter(line: number, character: number): number;

+>getPositionFromOneBasedLineAndCharacter : (line: number, character: number) => number
 >line : number
 >character : number
 
diff --git a/tests/baselines/reference/APISample_linter.js b/tests/baselines/reference/APISample_linter.js
index 68c13edb7db..0b090bebd7f 100644
--- a/tests/baselines/reference/APISample_linter.js
+++ b/tests/baselines/reference/APISample_linter.js
@@ -1415,14 +1415,14 @@ declare module "typescript" {
     }
     function tokenToString(t: SyntaxKind): string;
     function computeLineStarts(text: string): number[];
-    function getPositionFromLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;
-    function computePositionFromLineAndCharacter(lineStarts: number[], line: number, character: number): number;
+    function getPositionFromOneBasedLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;
+    function computePositionFromOneBasedLineAndCharacter(lineStarts: number[], line: number, character: number): number;
     function getLineStarts(sourceFile: SourceFile): number[];
-    function computeLineAndCharacterOfPosition(lineStarts: number[], position: number): {
+    function computeOneBasedLineAndCharacterOfPosition(lineStarts: number[], position: number): {
         line: number;
         character: number;
     };
-    function getLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;
+    function getOneBasedLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;
     function isWhiteSpace(ch: number): boolean;
     function isLineBreak(ch: number): boolean;
     function isOctalDigit(ch: number): boolean;
@@ -1502,7 +1502,7 @@ declare module "typescript" {
         getNamedDeclarations(): Declaration[];
         getLineAndCharacterFromPosition(pos: number): LineAndCharacter;
         getLineStarts(): number[];
-        getPositionFromLineAndCharacter(line: number, character: number): number;
+        getPositionFromOneBasedLineAndCharacter(line: number, character: number): number;
         update(newText: string, textChangeRange: TextChangeRange): SourceFile;
     }
     /**
diff --git a/tests/baselines/reference/APISample_linter.types b/tests/baselines/reference/APISample_linter.types
index 0c153e7b1dc..5e25227836b 100644
--- a/tests/baselines/reference/APISample_linter.types
+++ b/tests/baselines/reference/APISample_linter.types
@@ -4512,15 +4512,15 @@ declare module "typescript" {
 >computeLineStarts : (text: string) => number[]
 >text : string
 
-    function getPositionFromLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;

->getPositionFromLineAndCharacter : (sourceFile: SourceFile, line: number, character: number) => number
+    function getPositionFromOneBasedLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;

+>getPositionFromOneBasedLineAndCharacter : (sourceFile: SourceFile, line: number, character: number) => number
 >sourceFile : SourceFile
 >SourceFile : SourceFile
 >line : number
 >character : number
 
-    function computePositionFromLineAndCharacter(lineStarts: number[], line: number, character: number): number;

->computePositionFromLineAndCharacter : (lineStarts: number[], line: number, character: number) => number
+    function computePositionFromOneBasedLineAndCharacter(lineStarts: number[], line: number, character: number): number;

+>computePositionFromOneBasedLineAndCharacter : (lineStarts: number[], line: number, character: number) => number
 >lineStarts : number[]
 >line : number
 >character : number
@@ -4530,8 +4530,8 @@ declare module "typescript" {
 >sourceFile : SourceFile
 >SourceFile : SourceFile
 
-    function computeLineAndCharacterOfPosition(lineStarts: number[], position: number): {

->computeLineAndCharacterOfPosition : (lineStarts: number[], position: number) => { line: number; character: number; }
+    function computeOneBasedLineAndCharacterOfPosition(lineStarts: number[], position: number): {

+>computeOneBasedLineAndCharacterOfPosition : (lineStarts: number[], position: number) => { line: number; character: number; }
 >lineStarts : number[]
 >position : number
 
@@ -4542,8 +4542,8 @@ declare module "typescript" {
 >character : number
 
     };

-    function getLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;

->getLineAndCharacterOfPosition : (sourceFile: SourceFile, position: number) => LineAndCharacter
+    function getOneBasedLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;

+>getOneBasedLineAndCharacterOfPosition : (sourceFile: SourceFile, position: number) => LineAndCharacter
 >sourceFile : SourceFile
 >SourceFile : SourceFile
 >position : number
@@ -4887,8 +4887,8 @@ declare module "typescript" {
         getLineStarts(): number[];

 >getLineStarts : () => number[]
 
-        getPositionFromLineAndCharacter(line: number, character: number): number;

->getPositionFromLineAndCharacter : (line: number, character: number) => number
+        getPositionFromOneBasedLineAndCharacter(line: number, character: number): number;

+>getPositionFromOneBasedLineAndCharacter : (line: number, character: number) => number
 >line : number
 >character : number
 
diff --git a/tests/baselines/reference/APISample_transform.js b/tests/baselines/reference/APISample_transform.js
index 0e80f6b55b9..4e933d72b3e 100644
--- a/tests/baselines/reference/APISample_transform.js
+++ b/tests/baselines/reference/APISample_transform.js
@@ -1416,14 +1416,14 @@ declare module "typescript" {
     }
     function tokenToString(t: SyntaxKind): string;
     function computeLineStarts(text: string): number[];
-    function getPositionFromLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;
-    function computePositionFromLineAndCharacter(lineStarts: number[], line: number, character: number): number;
+    function getPositionFromOneBasedLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;
+    function computePositionFromOneBasedLineAndCharacter(lineStarts: number[], line: number, character: number): number;
     function getLineStarts(sourceFile: SourceFile): number[];
-    function computeLineAndCharacterOfPosition(lineStarts: number[], position: number): {
+    function computeOneBasedLineAndCharacterOfPosition(lineStarts: number[], position: number): {
         line: number;
         character: number;
     };
-    function getLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;
+    function getOneBasedLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;
     function isWhiteSpace(ch: number): boolean;
     function isLineBreak(ch: number): boolean;
     function isOctalDigit(ch: number): boolean;
@@ -1503,7 +1503,7 @@ declare module "typescript" {
         getNamedDeclarations(): Declaration[];
         getLineAndCharacterFromPosition(pos: number): LineAndCharacter;
         getLineStarts(): number[];
-        getPositionFromLineAndCharacter(line: number, character: number): number;
+        getPositionFromOneBasedLineAndCharacter(line: number, character: number): number;
         update(newText: string, textChangeRange: TextChangeRange): SourceFile;
     }
     /**
diff --git a/tests/baselines/reference/APISample_transform.types b/tests/baselines/reference/APISample_transform.types
index 0c201b0a5fd..5d39868e610 100644
--- a/tests/baselines/reference/APISample_transform.types
+++ b/tests/baselines/reference/APISample_transform.types
@@ -4464,15 +4464,15 @@ declare module "typescript" {
 >computeLineStarts : (text: string) => number[]
 >text : string
 
-    function getPositionFromLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;

->getPositionFromLineAndCharacter : (sourceFile: SourceFile, line: number, character: number) => number
+    function getPositionFromOneBasedLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;

+>getPositionFromOneBasedLineAndCharacter : (sourceFile: SourceFile, line: number, character: number) => number
 >sourceFile : SourceFile
 >SourceFile : SourceFile
 >line : number
 >character : number
 
-    function computePositionFromLineAndCharacter(lineStarts: number[], line: number, character: number): number;

->computePositionFromLineAndCharacter : (lineStarts: number[], line: number, character: number) => number
+    function computePositionFromOneBasedLineAndCharacter(lineStarts: number[], line: number, character: number): number;

+>computePositionFromOneBasedLineAndCharacter : (lineStarts: number[], line: number, character: number) => number
 >lineStarts : number[]
 >line : number
 >character : number
@@ -4482,8 +4482,8 @@ declare module "typescript" {
 >sourceFile : SourceFile
 >SourceFile : SourceFile
 
-    function computeLineAndCharacterOfPosition(lineStarts: number[], position: number): {

->computeLineAndCharacterOfPosition : (lineStarts: number[], position: number) => { line: number; character: number; }
+    function computeOneBasedLineAndCharacterOfPosition(lineStarts: number[], position: number): {

+>computeOneBasedLineAndCharacterOfPosition : (lineStarts: number[], position: number) => { line: number; character: number; }
 >lineStarts : number[]
 >position : number
 
@@ -4494,8 +4494,8 @@ declare module "typescript" {
 >character : number
 
     };

-    function getLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;

->getLineAndCharacterOfPosition : (sourceFile: SourceFile, position: number) => LineAndCharacter
+    function getOneBasedLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;

+>getOneBasedLineAndCharacterOfPosition : (sourceFile: SourceFile, position: number) => LineAndCharacter
 >sourceFile : SourceFile
 >SourceFile : SourceFile
 >position : number
@@ -4839,8 +4839,8 @@ declare module "typescript" {
         getLineStarts(): number[];

 >getLineStarts : () => number[]
 
-        getPositionFromLineAndCharacter(line: number, character: number): number;

->getPositionFromLineAndCharacter : (line: number, character: number) => number
+        getPositionFromOneBasedLineAndCharacter(line: number, character: number): number;

+>getPositionFromOneBasedLineAndCharacter : (line: number, character: number) => number
 >line : number
 >character : number
 
diff --git a/tests/baselines/reference/APISample_watcher.js b/tests/baselines/reference/APISample_watcher.js
index 27a2ce5e415..0ab43d3f64f 100644
--- a/tests/baselines/reference/APISample_watcher.js
+++ b/tests/baselines/reference/APISample_watcher.js
@@ -1453,14 +1453,14 @@ declare module "typescript" {
     }
     function tokenToString(t: SyntaxKind): string;
     function computeLineStarts(text: string): number[];
-    function getPositionFromLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;
-    function computePositionFromLineAndCharacter(lineStarts: number[], line: number, character: number): number;
+    function getPositionFromOneBasedLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;
+    function computePositionFromOneBasedLineAndCharacter(lineStarts: number[], line: number, character: number): number;
     function getLineStarts(sourceFile: SourceFile): number[];
-    function computeLineAndCharacterOfPosition(lineStarts: number[], position: number): {
+    function computeOneBasedLineAndCharacterOfPosition(lineStarts: number[], position: number): {
         line: number;
         character: number;
     };
-    function getLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;
+    function getOneBasedLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;
     function isWhiteSpace(ch: number): boolean;
     function isLineBreak(ch: number): boolean;
     function isOctalDigit(ch: number): boolean;
@@ -1540,7 +1540,7 @@ declare module "typescript" {
         getNamedDeclarations(): Declaration[];
         getLineAndCharacterFromPosition(pos: number): LineAndCharacter;
         getLineStarts(): number[];
-        getPositionFromLineAndCharacter(line: number, character: number): number;
+        getPositionFromOneBasedLineAndCharacter(line: number, character: number): number;
         update(newText: string, textChangeRange: TextChangeRange): SourceFile;
     }
     /**
diff --git a/tests/baselines/reference/APISample_watcher.types b/tests/baselines/reference/APISample_watcher.types
index 4e137cae59d..824ca033f2b 100644
--- a/tests/baselines/reference/APISample_watcher.types
+++ b/tests/baselines/reference/APISample_watcher.types
@@ -4637,15 +4637,15 @@ declare module "typescript" {
 >computeLineStarts : (text: string) => number[]
 >text : string
 
-    function getPositionFromLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;

->getPositionFromLineAndCharacter : (sourceFile: SourceFile, line: number, character: number) => number
+    function getPositionFromOneBasedLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number;

+>getPositionFromOneBasedLineAndCharacter : (sourceFile: SourceFile, line: number, character: number) => number
 >sourceFile : SourceFile
 >SourceFile : SourceFile
 >line : number
 >character : number
 
-    function computePositionFromLineAndCharacter(lineStarts: number[], line: number, character: number): number;

->computePositionFromLineAndCharacter : (lineStarts: number[], line: number, character: number) => number
+    function computePositionFromOneBasedLineAndCharacter(lineStarts: number[], line: number, character: number): number;

+>computePositionFromOneBasedLineAndCharacter : (lineStarts: number[], line: number, character: number) => number
 >lineStarts : number[]
 >line : number
 >character : number
@@ -4655,8 +4655,8 @@ declare module "typescript" {
 >sourceFile : SourceFile
 >SourceFile : SourceFile
 
-    function computeLineAndCharacterOfPosition(lineStarts: number[], position: number): {

->computeLineAndCharacterOfPosition : (lineStarts: number[], position: number) => { line: number; character: number; }
+    function computeOneBasedLineAndCharacterOfPosition(lineStarts: number[], position: number): {

+>computeOneBasedLineAndCharacterOfPosition : (lineStarts: number[], position: number) => { line: number; character: number; }
 >lineStarts : number[]
 >position : number
 
@@ -4667,8 +4667,8 @@ declare module "typescript" {
 >character : number
 
     };

-    function getLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;

->getLineAndCharacterOfPosition : (sourceFile: SourceFile, position: number) => LineAndCharacter
+    function getOneBasedLineAndCharacterOfPosition(sourceFile: SourceFile, position: number): LineAndCharacter;

+>getOneBasedLineAndCharacterOfPosition : (sourceFile: SourceFile, position: number) => LineAndCharacter
 >sourceFile : SourceFile
 >SourceFile : SourceFile
 >position : number
@@ -5012,8 +5012,8 @@ declare module "typescript" {
         getLineStarts(): number[];

 >getLineStarts : () => number[]
 
-        getPositionFromLineAndCharacter(line: number, character: number): number;

->getPositionFromLineAndCharacter : (line: number, character: number) => number
+        getPositionFromOneBasedLineAndCharacter(line: number, character: number): number;

+>getPositionFromOneBasedLineAndCharacter : (line: number, character: number) => number
 >line : number
 >character : number