From 22731a7588d771ac2fe5f351007e1939b61ff7fc Mon Sep 17 00:00:00 2001
From: Olivier Combe <olivier.combe@gmail.com>
Date: Thu, 19 Jul 2018 11:02:22 +0200
Subject: [PATCH] refactor(ivy): split i18nInterpolation into 8 functions
 (#24805)

PR Close #24805
---
 .../core/src/core_render3_private_export.ts   |   9 +-
 packages/core/src/render3/i18n.ts             | 372 +++++++++++++++---
 packages/core/src/render3/index.ts            |  11 +-
 packages/core/src/render3/instructions.ts     |   2 +-
 .../render3/compiler_canonical/i18n_spec.ts   |   2 +-
 packages/core/test/render3/i18n_spec.ts       | 320 +++++++++++++--
 6 files changed, 614 insertions(+), 102 deletions(-)

diff --git a/packages/core/src/core_render3_private_export.ts b/packages/core/src/core_render3_private_export.ts
index c88234bda0..8107ad315f 100644
--- a/packages/core/src/core_render3_private_export.ts
+++ b/packages/core/src/core_render3_private_export.ts
@@ -94,7 +94,14 @@ export {
   whenRendered as ɵwhenRendered,
   iA as ɵiA,
   iEM as ɵiEM,
-  iI as ɵiI,
+  iI1 as ɵiI1,
+  iI2 as ɵiI2,
+  iI3 as ɵiI3,
+  iI4 as ɵiI4,
+  iI5 as ɵiI5,
+  iI6 as ɵiI6,
+  iI7 as ɵiI7,
+  iI8 as ɵiI8,
   iIV as ɵIV,
   iM as ɵiM,
   I18nInstruction as ɵI18nInstruction,
diff --git a/packages/core/src/render3/i18n.ts b/packages/core/src/render3/i18n.ts
index 279c8d5b37..6c64793290 100644
--- a/packages/core/src/render3/i18n.ts
+++ b/packages/core/src/render3/i18n.ts
@@ -7,7 +7,7 @@
  */
 
 import {assertEqual, assertLessThan} from './assert';
-import {NO_CHANGE, bindingUpdated, createLNode, getPreviousOrParentNode, getRenderer, getViewData, load, resetApplicationState} from './instructions';
+import {NO_CHANGE, bindingUpdated, bindingUpdated2, bindingUpdated4, createLNode, getPreviousOrParentNode, getRenderer, getViewData, load, resetApplicationState} from './instructions';
 import {RENDER_PARENT} from './interfaces/container';
 import {LContainerNode, LNode, TContainerNode, TElementNode, TNodeType} from './interfaces/node';
 import {BINDING_INDEX, HEADER_OFFSET, TVIEW} from './interfaces/view';
@@ -369,43 +369,16 @@ export function i18nExpMapping(
 }
 
 /**
- * Checks if the value of up to 8 expressions have changed and replaces them by their values in a
- * translation, or returns NO_CHANGE.
+ * Checks if the value of an expression has changed and replaces it by its value in a translation,
+ * or returns NO_CHANGE.
+ *
+ * @param instructions A list of instructions that will be used to translate an attribute.
+ * @param v0 value checked for change.
  *
  * @returns The concatenated string when any of the arguments changes, `NO_CHANGE` otherwise.
  */
-export function i18nInterpolation(
-    instructions: I18nExpInstruction[], numberOfExp: number, v0: any, v1?: any, v2?: any, v3?: any,
-    v4?: any, v5?: any, v6?: any, v7?: any): string|NO_CHANGE {
-  let different = bindingUpdated(v0);
-
-  if (numberOfExp > 1) {
-    different = bindingUpdated(v1) || different;
-
-    if (numberOfExp > 2) {
-      different = bindingUpdated(v2) || different;
-
-      if (numberOfExp > 3) {
-        different = bindingUpdated(v3) || different;
-
-        if (numberOfExp > 4) {
-          different = bindingUpdated(v4) || different;
-
-          if (numberOfExp > 5) {
-            different = bindingUpdated(v5) || different;
-
-            if (numberOfExp > 6) {
-              different = bindingUpdated(v6) || different;
-
-              if (numberOfExp > 7) {
-                different = bindingUpdated(v7) || different;
-              }
-            }
-          }
-        }
-      }
-    }
-  }
+export function i18nInterpolation1(instructions: I18nExpInstruction[], v0: any): string|NO_CHANGE {
+  const different = bindingUpdated(v0);
 
   if (!different) {
     return NO_CHANGE;
@@ -413,35 +386,308 @@ export function i18nInterpolation(
 
   let res = '';
   for (let i = 0; i < instructions.length; i++) {
-    let value: any;
-    // Odd indexes are placeholders
+    // Odd indexes are bindings
     if (i & 1) {
-      switch (instructions[i]) {
-        case 0:
-          value = v0;
-          break;
-        case 1:
-          value = v1;
-          break;
-        case 2:
-          value = v2;
-          break;
-        case 3:
-          value = v3;
-          break;
-        case 4:
-          value = v4;
-          break;
-        case 5:
-          value = v5;
-          break;
-        case 6:
-          value = v6;
-          break;
-        case 7:
-          value = v7;
-          break;
-      }
+      res += stringify(v0);
+    } else {
+      res += instructions[i];
+    }
+  }
+
+  return res;
+}
+
+/**
+ * Checks if the values of up to 2 expressions have changed and replaces them by their values in a
+ * translation, or returns NO_CHANGE.
+ *
+ * @param instructions A list of instructions that will be used to translate an attribute.
+ * @param v0 value checked for change.
+ * @param v1 value checked for change.
+ *
+ * @returns The concatenated string when any of the arguments changes, `NO_CHANGE` otherwise.
+ */
+export function i18nInterpolation2(instructions: I18nExpInstruction[], v0: any, v1: any): string|
+    NO_CHANGE {
+  const different = bindingUpdated2(v0, v1);
+
+  if (!different) {
+    return NO_CHANGE;
+  }
+
+  let res = '';
+  for (let i = 0; i < instructions.length; i++) {
+    // Odd indexes are bindings
+    if (i & 1) {
+      // Extract bits
+      const idx = instructions[i] as number;
+      const b1 = idx & 1;
+      // Get the value from the argument vx where x = idx
+      const value = b1 ? v1 : v0;
+
+      res += stringify(value);
+    } else {
+      res += instructions[i];
+    }
+  }
+
+  return res;
+}
+
+/**
+ * Checks if the values of up to 3 expressions have changed and replaces them by their values in a
+ * translation, or returns NO_CHANGE.
+ *
+ * @param instructions A list of instructions that will be used to translate an attribute.
+ * @param v0 value checked for change.
+ * @param v1 value checked for change.
+ * @param v2 value checked for change.
+ *
+ * @returns The concatenated string when any of the arguments changes, `NO_CHANGE` otherwise.
+ */
+export function i18nInterpolation3(
+    instructions: I18nExpInstruction[], v0: any, v1: any, v2: any): string|NO_CHANGE {
+  let different = bindingUpdated2(v0, v1);
+  different = bindingUpdated(v2) || different;
+
+  if (!different) {
+    return NO_CHANGE;
+  }
+
+  let res = '';
+  for (let i = 0; i < instructions.length; i++) {
+    // Odd indexes are bindings
+    if (i & 1) {
+      // Extract bits
+      const idx = instructions[i] as number;
+      const b2 = idx & 2;
+      const b1 = idx & 1;
+      // Get the value from the argument vx where x = idx
+      const value = b2 ? v2 : (b1 ? v1 : v0);
+
+      res += stringify(value);
+    } else {
+      res += instructions[i];
+    }
+  }
+
+  return res;
+}
+
+/**
+ * Checks if the values of up to 4 expressions have changed and replaces them by their values in a
+ * translation, or returns NO_CHANGE.
+ *
+ * @param instructions A list of instructions that will be used to translate an attribute.
+ * @param v0 value checked for change.
+ * @param v1 value checked for change.
+ * @param v2 value checked for change.
+ * @param v3 value checked for change.
+ *
+ * @returns The concatenated string when any of the arguments changes, `NO_CHANGE` otherwise.
+ */
+export function i18nInterpolation4(
+    instructions: I18nExpInstruction[], v0: any, v1: any, v2: any, v3: any): string|NO_CHANGE {
+  const different = bindingUpdated4(v0, v1, v2, v3);
+
+  if (!different) {
+    return NO_CHANGE;
+  }
+
+  let res = '';
+  for (let i = 0; i < instructions.length; i++) {
+    // Odd indexes are bindings
+    if (i & 1) {
+      // Extract bits
+      const idx = instructions[i] as number;
+      const b2 = idx & 2;
+      const b1 = idx & 1;
+      // Get the value from the argument vx where x = idx
+      const value = b2 ? (b1 ? v3 : v2) : (b1 ? v1 : v0);
+
+      res += stringify(value);
+    } else {
+      res += instructions[i];
+    }
+  }
+
+  return res;
+}
+
+/**
+ * Checks if the values of up to 5 expressions have changed and replaces them by their values in a
+ * translation, or returns NO_CHANGE.
+ *
+ * @param instructions A list of instructions that will be used to translate an attribute.
+ * @param v0 value checked for change.
+ * @param v1 value checked for change.
+ * @param v2 value checked for change.
+ * @param v3 value checked for change.
+ * @param v4 value checked for change.
+ *
+ * @returns The concatenated string when any of the arguments changes, `NO_CHANGE` otherwise.
+ */
+export function i18nInterpolation5(
+    instructions: I18nExpInstruction[], v0: any, v1: any, v2: any, v3: any, v4: any): string|
+    NO_CHANGE {
+  let different = bindingUpdated4(v0, v1, v2, v3);
+  different = bindingUpdated(v4) || different;
+
+  if (!different) {
+    return NO_CHANGE;
+  }
+
+  let res = '';
+  for (let i = 0; i < instructions.length; i++) {
+    // Odd indexes are bindings
+    if (i & 1) {
+      // Extract bits
+      const idx = instructions[i] as number;
+      const b4 = idx & 4;
+      const b2 = idx & 2;
+      const b1 = idx & 1;
+      // Get the value from the argument vx where x = idx
+      const value = b4 ? v4 : (b2 ? (b1 ? v3 : v2) : (b1 ? v1 : v0));
+
+      res += stringify(value);
+    } else {
+      res += instructions[i];
+    }
+  }
+
+  return res;
+}
+
+/**
+ * Checks if the values of up to 6 expressions have changed and replaces them by their values in a
+ * translation, or returns NO_CHANGE.
+ *
+ * @param instructions A list of instructions that will be used to translate an attribute.
+ * @param v0 value checked for change.
+ * @param v1 value checked for change.
+ * @param v2 value checked for change.
+ * @param v3 value checked for change.
+ * @param v4 value checked for change.
+ * @param v5 value checked for change.
+ *
+ * @returns The concatenated string when any of the arguments changes, `NO_CHANGE` otherwise.
+ */ export function
+i18nInterpolation6(
+    instructions: I18nExpInstruction[], v0: any, v1: any, v2: any, v3: any, v4: any, v5: any):
+    string|NO_CHANGE {
+  let different = bindingUpdated4(v0, v1, v2, v3);
+  different = bindingUpdated2(v4, v5) || different;
+
+  if (!different) {
+    return NO_CHANGE;
+  }
+
+  let res = '';
+  for (let i = 0; i < instructions.length; i++) {
+    // Odd indexes are bindings
+    if (i & 1) {
+      // Extract bits
+      const idx = instructions[i] as number;
+      const b4 = idx & 4;
+      const b2 = idx & 2;
+      const b1 = idx & 1;
+      // Get the value from the argument vx where x = idx
+      const value = b4 ? (b1 ? v5 : v4) : (b2 ? (b1 ? v3 : v2) : (b1 ? v1 : v0));
+
+      res += stringify(value);
+    } else {
+      res += instructions[i];
+    }
+  }
+
+  return res;
+}
+
+/**
+ * Checks if the values of up to 7 expressions have changed and replaces them by their values in a
+ * translation, or returns NO_CHANGE.
+ *
+ * @param instructions A list of instructions that will be used to translate an attribute.
+ * @param v0 value checked for change.
+ * @param v1 value checked for change.
+ * @param v2 value checked for change.
+ * @param v3 value checked for change.
+ * @param v4 value checked for change.
+ * @param v5 value checked for change.
+ * @param v6 value checked for change.
+ *
+ * @returns The concatenated string when any of the arguments changes, `NO_CHANGE` otherwise.
+ */
+export function i18nInterpolation7(
+    instructions: I18nExpInstruction[], v0: any, v1: any, v2: any, v3: any, v4: any, v5: any,
+    v6: any): string|NO_CHANGE {
+  let different = bindingUpdated4(v0, v1, v2, v3);
+  different = bindingUpdated2(v4, v5) || different;
+  different = bindingUpdated(v6) || different;
+
+  if (!different) {
+    return NO_CHANGE;
+  }
+
+  let res = '';
+  for (let i = 0; i < instructions.length; i++) {
+    // Odd indexes are bindings
+    if (i & 1) {
+      // Extract bits
+      const idx = instructions[i] as number;
+      const b4 = idx & 4;
+      const b2 = idx & 2;
+      const b1 = idx & 1;
+      // Get the value from the argument vx where x = idx
+      const value = b4 ? (b2 ? v6 : (b1 ? v5 : v4)) : (b2 ? (b1 ? v3 : v2) : (b1 ? v1 : v0));
+
+      res += stringify(value);
+    } else {
+      res += instructions[i];
+    }
+  }
+
+  return res;
+}
+
+/**
+ * Checks if the values of up to 8 expressions have changed and replaces them by their values in a
+ * translation, or returns NO_CHANGE.
+ *
+ * @param instructions A list of instructions that will be used to translate an attribute.
+ * @param v0 value checked for change.
+ * @param v1 value checked for change.
+ * @param v2 value checked for change.
+ * @param v3 value checked for change.
+ * @param v4 value checked for change.
+ * @param v5 value checked for change.
+ * @param v6 value checked for change.
+ * @param v7 value checked for change.
+ *
+ * @returns The concatenated string when any of the arguments changes, `NO_CHANGE` otherwise.
+ */
+export function i18nInterpolation8(
+    instructions: I18nExpInstruction[], v0: any, v1: any, v2: any, v3: any, v4: any, v5: any,
+    v6: any, v7: any): string|NO_CHANGE {
+  let different = bindingUpdated4(v0, v1, v2, v3);
+  different = bindingUpdated4(v4, v5, v6, v7) || different;
+
+  if (!different) {
+    return NO_CHANGE;
+  }
+
+  let res = '';
+  for (let i = 0; i < instructions.length; i++) {
+    // Odd indexes are bindings
+    if (i & 1) {
+      // Extract bits
+      const idx = instructions[i] as number;
+      const b4 = idx & 4;
+      const b2 = idx & 2;
+      const b1 = idx & 1;
+      // Get the value from the argument vx where x = idx
+      const value =
+          b4 ? (b2 ? (b1 ? v7 : v6) : (b1 ? v5 : v4)) : (b2 ? (b1 ? v3 : v2) : (b1 ? v1 : v0));
 
       res += stringify(value);
     } else {
diff --git a/packages/core/src/render3/index.ts b/packages/core/src/render3/index.ts
index 014a092e66..70ba550eb3 100644
--- a/packages/core/src/render3/index.ts
+++ b/packages/core/src/render3/index.ts
@@ -11,7 +11,7 @@ import {defineComponent, defineDirective, defineNgModule, definePipe} from './de
 import {InheritDefinitionFeature} from './features/inherit_definition_feature';
 import {NgOnChangesFeature} from './features/ng_onchanges_feature';
 import {PublicFeature} from './features/public_feature';
-import {I18nExpInstruction, I18nInstruction, i18nExpMapping, i18nInterpolation, i18nInterpolationV} from './i18n';
+import {I18nExpInstruction, I18nInstruction, i18nExpMapping, i18nInterpolation1, i18nInterpolation2, i18nInterpolation3, i18nInterpolation4, i18nInterpolation5, i18nInterpolation6, i18nInterpolation7, i18nInterpolation8, i18nInterpolationV} from './i18n';
 import {ComponentDef, ComponentDefInternal, ComponentTemplate, ComponentType, DirectiveDef, DirectiveDefFlags, DirectiveDefInternal, DirectiveType, PipeDef} from './interfaces/definition';
 
 export {ComponentFactory, ComponentFactoryResolver, ComponentRef} from './component_ref';
@@ -88,7 +88,14 @@ export {
 export {
   i18nApply as iA,
   i18nMapping as iM,
-  i18nInterpolation as iI,
+  i18nInterpolation1 as iI1,
+  i18nInterpolation2 as iI2,
+  i18nInterpolation3 as iI3,
+  i18nInterpolation4 as iI4,
+  i18nInterpolation5 as iI5,
+  i18nInterpolation6 as iI6,
+  i18nInterpolation7 as iI7,
+  i18nInterpolation8 as iI8,
   i18nInterpolationV as iIV,
   i18nExpMapping as iEM,
   I18nInstruction,
diff --git a/packages/core/src/render3/instructions.ts b/packages/core/src/render3/instructions.ts
index 3b27b0d5d8..f99b34be06 100644
--- a/packages/core/src/render3/instructions.ts
+++ b/packages/core/src/render3/instructions.ts
@@ -2454,7 +2454,7 @@ export function interpolation2(
   return different ? prefix + stringify(v0) + i0 + stringify(v1) + suffix : NO_CHANGE;
 }
 
-/** Creates an interpolation bindings with 3 expressions. */
+/** Creates an interpolation binding with 3 expressions. */
 export function interpolation3(
     prefix: string, v0: any, i0: string, v1: any, i1: string, v2: any, suffix: string): string|
     NO_CHANGE {
diff --git a/packages/core/test/render3/compiler_canonical/i18n_spec.ts b/packages/core/test/render3/compiler_canonical/i18n_spec.ts
index 3811eb5c18..a27ddb89d2 100644
--- a/packages/core/test/render3/compiler_canonical/i18n_spec.ts
+++ b/packages/core/test/render3/compiler_canonical/i18n_spec.ts
@@ -86,7 +86,7 @@ describe('i18n', () => {
             $r3$.ɵe();
           }
           if (rf & 2) {
-            $r3$.ɵp(0, 'title', $r3$.ɵiI($i18n_1$, 2, ctx.exp1));
+            $r3$.ɵp(0, 'title', $r3$.ɵiI1($i18n_1$, ctx.exp1));
           }
         }
       });
diff --git a/packages/core/test/render3/i18n_spec.ts b/packages/core/test/render3/i18n_spec.ts
index d5709c2bd4..d185583385 100644
--- a/packages/core/test/render3/i18n_spec.ts
+++ b/packages/core/test/render3/i18n_spec.ts
@@ -9,7 +9,7 @@
 import {NgForOfContext} from '@angular/common';
 import {Component} from '../../src/core';
 import {defineComponent} from '../../src/render3/definition';
-import {I18nExpInstruction, I18nInstruction, i18nApply, i18nExpMapping, i18nInterpolation, i18nInterpolationV, i18nMapping} from '../../src/render3/i18n';
+import {I18nExpInstruction, I18nInstruction, i18nApply, i18nExpMapping, i18nInterpolation1, i18nInterpolation2, i18nInterpolation3, i18nInterpolation4, i18nInterpolation5, i18nInterpolation6, i18nInterpolation7, i18nInterpolation8, i18nInterpolationV, i18nMapping} from '../../src/render3/i18n';
 import {bind, container, containerRefreshEnd, containerRefreshStart, element, elementEnd, elementProperty, elementStart, embeddedViewEnd, embeddedViewStart, projection, projectionDef, text, textBinding} from '../../src/render3/instructions';
 import {RenderFlags} from '../../src/render3/interfaces/definition';
 import {NgForOf} from './common_with_def';
@@ -201,7 +201,7 @@ describe('Runtime i18n', () => {
             element(0, 'div');  // translated section 1
           }
           if (rf & RenderFlags.Update) {
-            elementProperty(0, 'title', i18nInterpolation(i18n_1, 2, ctx.exp1, ctx.exp2));
+            elementProperty(0, 'title', i18nInterpolation2(i18n_1, ctx.exp1, ctx.exp2));
           }
         }
       });
@@ -295,7 +295,7 @@ describe('Runtime i18n', () => {
             textBinding(1, bind(ctx.exp1));
             textBinding(6, bind(ctx.exp2));
             textBinding(7, bind(ctx.exp3));
-            elementProperty(0, 'title', i18nInterpolation(i18n_2, 2, ctx.exp1, ctx.exp2));
+            elementProperty(0, 'title', i18nInterpolation2(i18n_2, ctx.exp1, ctx.exp2));
           }
         }
       });
@@ -389,7 +389,7 @@ describe('Runtime i18n', () => {
           }
           if (rf & RenderFlags.Update) {
             textBinding(2, bind(ctx.exp1));
-            elementProperty(4, 'title', i18nInterpolation(i18n_3, 2, ctx.exp1, ctx.exp2));
+            elementProperty(4, 'title', i18nInterpolation2(i18n_3, ctx.exp1, ctx.exp2));
           }
         }
       });
@@ -1097,7 +1097,7 @@ describe('Runtime i18n', () => {
               i18nApply(1, i18n_1[0]);
             }
             if (rf & RenderFlags.Update) {
-              elementProperty(2, 'title', i18nInterpolation(i18n_2, 1, cmp.name));
+              elementProperty(2, 'title', i18nInterpolation1(i18n_2, cmp.name));
               textBinding(3, bind(cmp.name));
             }
           }
@@ -1184,7 +1184,7 @@ describe('Runtime i18n', () => {
               i18nApply(4, i18n_1[0]);
             }
             if (rf & RenderFlags.Update) {
-              elementProperty(3, 'title', i18nInterpolation(i18n_2, 1, cmp.name));
+              elementProperty(3, 'title', i18nInterpolation1(i18n_2, cmp.name));
               textBinding(4, bind(cmp.name));
             }
           }
@@ -1340,40 +1340,292 @@ describe('Runtime i18n', () => {
     });
   });
 
-  it('i18nInterpolation should return the same value as i18nInterpolationV', () => {
-    const MSG_DIV_SECTION_1 = `start {$EXP_2} middle {$EXP_1} end`;
-    const i18n_1 = i18nExpMapping(MSG_DIV_SECTION_1, {'EXP_1': 0, 'EXP_2': 1});
-    let interpolation;
-    let interpolationV;
+  describe('i18nInterpolation', () => {
+    it('i18nInterpolation should return the same value as i18nInterpolationV', () => {
+      const MSG_DIV_SECTION_1 = `start {$EXP_2} middle {$EXP_1} end`;
+      const i18n_1 = i18nExpMapping(MSG_DIV_SECTION_1, {'EXP_1': 0, 'EXP_2': 1});
+      let interpolation;
+      let interpolationV;
 
-    class MyApp {
-      exp1: any = '1';
-      exp2: any = '2';
+      class MyApp {
+        exp1: any = '1';
+        exp2: any = '2';
 
-      static ngComponentDef = defineComponent({
-        type: MyApp,
-        factory: () => new MyApp(),
-        selectors: [['my-app']],
-        // Initial template:
-        // <div i18n i18n-title title="{{exp1}}{{exp2}}"></div>
+        static ngComponentDef = defineComponent({
+          type: MyApp,
+          factory: () => new MyApp(),
+          selectors: [['my-app']],
+          // Initial template:
+          // <div i18n i18n-title title="{{exp1}}{{exp2}}"></div>
 
-        // Translated to:
-        // <div i18n i18n-title title="start {{exp2}} middle {{exp1}} end"></div>
-        template: (rf: RenderFlags, ctx: MyApp) => {
-          if (rf & RenderFlags.Create) {
-            element(0, 'div');  // translated section 1
+          // Translated to:
+          // <div i18n i18n-title title="start {{exp2}} middle {{exp1}} end"></div>
+          template: (rf: RenderFlags, ctx: MyApp) => {
+            if (rf & RenderFlags.Create) {
+              element(0, 'div');  // translated section 1
+            }
+            if (rf & RenderFlags.Update) {
+              interpolation = i18nInterpolation2(i18n_1, ctx.exp1, ctx.exp2);
+              interpolationV = i18nInterpolationV(i18n_1, [ctx.exp1, ctx.exp2]);
+              elementProperty(0, 'title', interpolation);
+            }
           }
-          if (rf & RenderFlags.Update) {
-            interpolation = i18nInterpolation(i18n_1, 2, ctx.exp1, ctx.exp2);
-            interpolationV = i18nInterpolationV(i18n_1, [ctx.exp1, ctx.exp2]);
-            elementProperty(0, 'title', interpolation);
+        });
+      }
+
+      const fixture = new ComponentFixture(MyApp);
+      expect(interpolation).toBeDefined();
+      expect(interpolation).toEqual(interpolationV);
+    });
+
+    it('i18nInterpolation3 should work', () => {
+      const MSG_DIV_SECTION_1 = `start {$EXP_1} _ {$EXP_2} _ {$EXP_3} end`;
+      const i18n_1 = i18nExpMapping(MSG_DIV_SECTION_1, {'EXP_1': 0, 'EXP_2': 1, 'EXP_3': 2});
+
+      class MyApp {
+        exp1: any = '1';
+        exp2: any = '2';
+        exp3: any = '3';
+
+        static ngComponentDef = defineComponent({
+          type: MyApp,
+          factory: () => new MyApp(),
+          selectors: [['my-app']],
+          // Initial template:
+          // <div i18n i18n-title title="{{exp1}}{{exp2}}{{exp3}}"></div>
+
+          // Translated to:
+          // <div i18n i18n-title title="start {{exp1}} _ {{exp2}} _ {{exp3}} end"></div>
+          template: (rf: RenderFlags, ctx: MyApp) => {
+            if (rf & RenderFlags.Create) {
+              element(0, 'div');  // translated section 1
+            }
+            if (rf & RenderFlags.Update) {
+              elementProperty(0, 'title', i18nInterpolation3(i18n_1, ctx.exp1, ctx.exp2, ctx.exp3));
+            }
           }
-        }
+        });
+      }
+
+      const fixture = new ComponentFixture(MyApp);
+      expect(fixture.html).toEqual('<div title="start 1 _ 2 _ 3 end"></div>');
+    });
+
+    it('i18nInterpolation4 should work', () => {
+      const MSG_DIV_SECTION_1 = `start {$EXP_1} _ {$EXP_2} _ {$EXP_3} _ {$EXP_4} end`;
+      const i18n_1 =
+          i18nExpMapping(MSG_DIV_SECTION_1, {'EXP_1': 0, 'EXP_2': 1, 'EXP_3': 2, 'EXP_4': 3});
+
+      class MyApp {
+        exp1: any = '1';
+        exp2: any = '2';
+        exp3: any = '3';
+        exp4: any = '4';
+
+        static ngComponentDef = defineComponent({
+          type: MyApp,
+          factory: () => new MyApp(),
+          selectors: [['my-app']],
+          // Initial template:
+          // <div i18n i18n-title title="{{exp1}}{{exp2}}{{exp3}}{{exp4}}"></div>
+
+          // Translated to:
+          // <div i18n i18n-title title="start {{exp1}} _ {{exp2}} _ {{exp3}} _ {{exp4}} end"></div>
+          template: (rf: RenderFlags, ctx: MyApp) => {
+            if (rf & RenderFlags.Create) {
+              element(0, 'div');  // translated section 1
+            }
+            if (rf & RenderFlags.Update) {
+              elementProperty(
+                  0, 'title', i18nInterpolation4(i18n_1, ctx.exp1, ctx.exp2, ctx.exp3, ctx.exp4));
+            }
+          }
+        });
+      }
+
+      const fixture = new ComponentFixture(MyApp);
+      expect(fixture.html).toEqual('<div title="start 1 _ 2 _ 3 _ 4 end"></div>');
+    });
+
+    it('i18nInterpolation5 should work', () => {
+      const MSG_DIV_SECTION_1 = `start {$EXP_1} _ {$EXP_2} _ {$EXP_3} _ {$EXP_4} _ {$EXP_5} end`;
+      const i18n_1 = i18nExpMapping(
+          MSG_DIV_SECTION_1, {'EXP_1': 0, 'EXP_2': 1, 'EXP_3': 2, 'EXP_4': 3, 'EXP_5': 4});
+
+      class MyApp {
+        exp1: any = '1';
+        exp2: any = '2';
+        exp3: any = '3';
+        exp4: any = '4';
+        exp5: any = '5';
+
+        static ngComponentDef = defineComponent({
+          type: MyApp,
+          factory: () => new MyApp(),
+          selectors: [['my-app']],
+          // Initial template:
+          // <div i18n i18n-title title="{{exp1}}{{exp2}}{{exp3}}{{exp4}}{{exp5}}"></div>
+
+          // Translated to:
+          // <div i18n i18n-title title="start {{exp1}} _ {{exp2}} _ {{exp3}} _ {{exp4}} _ {{exp5}}
+          // end"></div>
+          template: (rf: RenderFlags, ctx: MyApp) => {
+            if (rf & RenderFlags.Create) {
+              element(0, 'div');  // translated section 1
+            }
+            if (rf & RenderFlags.Update) {
+              elementProperty(
+                  0, 'title',
+                  i18nInterpolation5(i18n_1, ctx.exp1, ctx.exp2, ctx.exp3, ctx.exp4, ctx.exp5));
+            }
+          }
+        });
+      }
+
+      const fixture = new ComponentFixture(MyApp);
+      expect(fixture.html).toEqual('<div title="start 1 _ 2 _ 3 _ 4 _ 5 end"></div>');
+    });
+
+    it('i18nInterpolation6 should work', () => {
+      const MSG_DIV_SECTION_1 =
+          `start {$EXP_1} _ {$EXP_2} _ {$EXP_3} _ {$EXP_4} _ {$EXP_5} _ {$EXP_6} end`;
+      const i18n_1 = i18nExpMapping(
+          MSG_DIV_SECTION_1,
+          {'EXP_1': 0, 'EXP_2': 1, 'EXP_3': 2, 'EXP_4': 3, 'EXP_5': 4, 'EXP_6': 5});
+
+      class MyApp {
+        exp1: any = '1';
+        exp2: any = '2';
+        exp3: any = '3';
+        exp4: any = '4';
+        exp5: any = '5';
+        exp6: any = '6';
+
+        static ngComponentDef = defineComponent({
+          type: MyApp,
+          factory: () => new MyApp(),
+          selectors: [['my-app']],
+          // Initial template:
+          // <div i18n i18n-title title="{{exp1}}{{exp2}}{{exp3}}{{exp4}}{{exp5}}{{exp6}}"></div>
+
+          // Translated to:
+          // <div i18n i18n-title title="start {{exp1}} _ {{exp2}} _ {{exp3}} _ {{exp4}} _ {{exp5}}
+          // _ {{exp6}} end"></div>
+          template: (rf: RenderFlags, ctx: MyApp) => {
+            if (rf & RenderFlags.Create) {
+              element(0, 'div');  // translated section 1
+            }
+            if (rf & RenderFlags.Update) {
+              elementProperty(
+                  0, 'title',
+                  i18nInterpolation6(
+                      i18n_1, ctx.exp1, ctx.exp2, ctx.exp3, ctx.exp4, ctx.exp5, ctx.exp6));
+            }
+          }
+        });
+      }
+
+      const fixture = new ComponentFixture(MyApp);
+      expect(fixture.html).toEqual('<div title="start 1 _ 2 _ 3 _ 4 _ 5 _ 6 end"></div>');
+    });
+
+    it('i18nInterpolation7 should work', () => {
+      const MSG_DIV_SECTION_1 =
+          `start {$EXP_1} _ {$EXP_2} _ {$EXP_3} _ {$EXP_4} _ {$EXP_5} _ {$EXP_6} _ {$EXP_7} end`;
+      const i18n_1 = i18nExpMapping(
+          MSG_DIV_SECTION_1,
+          {'EXP_1': 0, 'EXP_2': 1, 'EXP_3': 2, 'EXP_4': 3, 'EXP_5': 4, 'EXP_6': 5, 'EXP_7': 6});
+
+      class MyApp {
+        exp1: any = '1';
+        exp2: any = '2';
+        exp3: any = '3';
+        exp4: any = '4';
+        exp5: any = '5';
+        exp6: any = '6';
+        exp7: any = '7';
+
+        static ngComponentDef = defineComponent({
+          type: MyApp,
+          factory: () => new MyApp(),
+          selectors: [['my-app']],
+          // Initial template:
+          // <div i18n i18n-title
+          // title="{{exp1}}{{exp2}}{{exp3}}{{exp4}}{{exp5}}{{exp6}}{{exp7}}"></div>
+
+          // Translated to:
+          // <div i18n i18n-title title="start {{exp1}} _ {{exp2}} _ {{exp3}} _ {{exp4}} _ {{exp5}}
+          // _ {{exp6}} _ {{exp7}} end"></div>
+          template: (rf: RenderFlags, ctx: MyApp) => {
+            if (rf & RenderFlags.Create) {
+              element(0, 'div');  // translated section 1
+            }
+            if (rf & RenderFlags.Update) {
+              elementProperty(
+                  0, 'title', i18nInterpolation7(
+                                  i18n_1, ctx.exp1, ctx.exp2, ctx.exp3, ctx.exp4, ctx.exp5,
+                                  ctx.exp6, ctx.exp7));
+            }
+          }
+        });
+      }
+
+      const fixture = new ComponentFixture(MyApp);
+      expect(fixture.html).toEqual('<div title="start 1 _ 2 _ 3 _ 4 _ 5 _ 6 _ 7 end"></div>');
+    });
+
+    it('i18nInterpolation8 should work', () => {
+      const MSG_DIV_SECTION_1 =
+          `start {$EXP_1} _ {$EXP_2} _ {$EXP_3} _ {$EXP_4} _ {$EXP_5} _ {$EXP_6} _ {$EXP_7} _ {$EXP_8} end`;
+      const i18n_1 = i18nExpMapping(MSG_DIV_SECTION_1, {
+        'EXP_1': 0,
+        'EXP_2': 1,
+        'EXP_3': 2,
+        'EXP_4': 3,
+        'EXP_5': 4,
+        'EXP_6': 5,
+        'EXP_7': 6,
+        'EXP_8': 7
       });
-    }
 
-    const fixture = new ComponentFixture(MyApp);
-    expect(interpolation).toBeDefined();
-    expect(interpolation).toEqual(interpolationV);
+      class MyApp {
+        exp1: any = '1';
+        exp2: any = '2';
+        exp3: any = '3';
+        exp4: any = '4';
+        exp5: any = '5';
+        exp6: any = '6';
+        exp7: any = '7';
+        exp8: any = '8';
+
+        static ngComponentDef = defineComponent({
+          type: MyApp,
+          factory: () => new MyApp(),
+          selectors: [['my-app']],
+          // Initial template:
+          // <div i18n i18n-title
+          // title="{{exp1}}{{exp2}}{{exp3}}{{exp4}}{{exp5}}{{exp6}}{{exp7}}{{exp8}}"></div>
+
+          // Translated to:
+          // <div i18n i18n-title title="start {{exp1}} _ {{exp2}} _ {{exp3}} _ {{exp4}} _ {{exp5}}
+          // _ {{exp6}} _ {{exp7}} _ {{exp8}} end"></div>
+          template: (rf: RenderFlags, ctx: MyApp) => {
+            if (rf & RenderFlags.Create) {
+              element(0, 'div');  // translated section 1
+            }
+            if (rf & RenderFlags.Update) {
+              elementProperty(
+                  0, 'title', i18nInterpolation8(
+                                  i18n_1, ctx.exp1, ctx.exp2, ctx.exp3, ctx.exp4, ctx.exp5,
+                                  ctx.exp6, ctx.exp7, ctx.exp8));
+            }
+          }
+        });
+      }
+
+      const fixture = new ComponentFixture(MyApp);
+      expect(fixture.html).toEqual('<div title="start 1 _ 2 _ 3 _ 4 _ 5 _ 6 _ 7 _ 8 end"></div>');
+    });
+
   });
 });