handle multiple prologue directives

ajafff · ajafff · commit f9eb976319b0 · 2018-07-10T22:42:21.000+02:00
Fixes: microsoft#24689
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
@@ -401,21 +401,18 @@ namespace ts {
     }
 
     /**
-     * Appends a range of value to begin of an array, returning the array.
-     *
-     * @param to The array to which `value` is to be appended. If `to` is `undefined`, a new array
-     * is created if `value` was appended.
-     * @param from The values to append to the array. If `from` is `undefined`, nothing is
-     * appended. If an element of `from` is `undefined`, that element is not appended.
+     * Prepends statements to an array taking care of prologue directives.
      */
-    export function prependStatements<T extends Statement>(to: T[], from: ReadonlyArray<T> | undefined): T[] | undefined {
+    export function prependStatements<T extends Statement>(to: T[], from: ReadonlyArray<T> | undefined): T[] {
         if (from === undefined || from.length === 0) return to;
-        if (to === undefined) return from.slice();
-        const prologue = to.length && isPrologueDirective(to[0]) && to.shift();
-        to.unshift(...from);
-        if (prologue) {
-            to.unshift(prologue);
+        let statementIndex = 0;
+        // skip all prologue directives to insert at the correct position
+        for (; statementIndex < to.length; ++statementIndex) {
+            if (!isPrologueDirective(to[statementIndex])) {
+                break;
+            }
         }
+        to.splice(statementIndex, 0, ...from);
         return to;
     }
 
diff --git a/tests/baselines/reference/api/tsserverlibrary.d.ts b/tests/baselines/reference/api/tsserverlibrary.d.ts
@@ -6094,14 +6094,9 @@ declare namespace ts {
     function nodeIsMissing(node: Node | undefined): boolean;
     function nodeIsPresent(node: Node | undefined): boolean;
     /**
-     * Appends a range of value to begin of an array, returning the array.
-     *
-     * @param to The array to which `value` is to be appended. If `to` is `undefined`, a new array
-     * is created if `value` was appended.
-     * @param from The values to append to the array. If `from` is `undefined`, nothing is
-     * appended. If an element of `from` is `undefined`, that element is not appended.
+     * Prepends statements to an array taking care of prologue directives.
      */
-    function prependStatements<T extends Statement>(to: T[], from: ReadonlyArray<T> | undefined): T[] | undefined;
+    function prependStatements<T extends Statement>(to: T[], from: ReadonlyArray<T> | undefined): T[];
     /**
      * Determine if the given comment is a triple-slash
      *
diff --git a/tests/baselines/reference/destructuringTempOccursAfterPrologue.js b/tests/baselines/reference/destructuringTempOccursAfterPrologue.js
@@ -1,12 +1,14 @@
 //// [destructuringTempOccursAfterPrologue.ts]
 function test(p: any) {
     'use strict';
+    'use strong';
     p = { prop: p } = p;
 }
 
 //// [destructuringTempOccursAfterPrologue.js]
 function test(p) {
     'use strict';
+    'use strong';
     var _a;
     p = (_a = p, p = _a.prop, _a);
 }
diff --git a/tests/baselines/reference/destructuringTempOccursAfterPrologue.symbols b/tests/baselines/reference/destructuringTempOccursAfterPrologue.symbols
@@ -4,9 +4,10 @@ function test(p: any) {
 >p : Symbol(p, Decl(destructuringTempOccursAfterPrologue.ts, 0, 14))
 
     'use strict';
+    'use strong';
     p = { prop: p } = p;
 >p : Symbol(p, Decl(destructuringTempOccursAfterPrologue.ts, 0, 14))
->prop : Symbol(prop, Decl(destructuringTempOccursAfterPrologue.ts, 2, 9))
+>prop : Symbol(prop, Decl(destructuringTempOccursAfterPrologue.ts, 3, 9))
 >p : Symbol(p, Decl(destructuringTempOccursAfterPrologue.ts, 0, 14))
 >p : Symbol(p, Decl(destructuringTempOccursAfterPrologue.ts, 0, 14))
 }
diff --git a/tests/baselines/reference/destructuringTempOccursAfterPrologue.types b/tests/baselines/reference/destructuringTempOccursAfterPrologue.types
@@ -6,6 +6,9 @@ function test(p: any) {
     'use strict';
 >'use strict' : "use strict"
 
+    'use strong';
+>'use strong' : "use strong"
+
     p = { prop: p } = p;
 >p = { prop: p } = p : any
 >p : any
diff --git a/tests/cases/compiler/destructuringTempOccursAfterPrologue.ts b/tests/cases/compiler/destructuringTempOccursAfterPrologue.ts
@@ -1,4 +1,5 @@
 function test(p: any) {
     'use strict';
+    'use strong';
     p = { prop: p } = p;
 }

Original file line number	Diff line number	Diff line change
`@@ -1,12 +1,14 @@`
`1`	`1`	`//// [destructuringTempOccursAfterPrologue.ts]`
`2`	`2`	`function test(p: any) {`
`3`	`3`	`'use strict';`
	`4`	`+ 'use strong';`
`4`	`5`	`p = { prop: p } = p;`
`5`	`6`	`}`
`6`	`7`
`7`	`8`	`//// [destructuringTempOccursAfterPrologue.js]`
`8`	`9`	`function test(p) {`
`9`	`10`	`'use strict';`
	`11`	`+ 'use strong';`
`10`	`12`	`var _a;`
`11`	`13`	`p = (_a = p, p = _a.prop, _a);`
`12`	`14`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,5 @@`
`1`	`1`	`function test(p: any) {`
`2`	`2`	`'use strict';`
	`3`	`+ 'use strong';`
`3`	`4`	`p = { prop: p } = p;`
`4`	`5`	`}`